“双减”政策自发布就吸引了社会的关注，对于学生而言，“双减”政策是要减轻其负担，但对于学校反而提出了更高的要求：学校要提高授课质量、优化授课技巧、提高作业质量，还要全面推广课后服务，以解决“三点半难题”。课后服务与不同于学校的常规课程，尤其是非学科类的课程与活动，对于长期从事学科教育的学校教师挑战很大。在这一背景下，大量的学校开始选择与社会机构合作提供课后服务。通过回顾整个的合作过程，分析各主体的权力与责任，梳理出合作的动力、沟通机制分析其中存在的问题与困境。在政策开放的情况下，很多学校在政府购买服务的框架下与社会力量合作提供课后服务。本文选取S 市与同一社会力量合作的6 所小学，在合作的前、中、后期，按合作主体身份属性分别进行访谈获取原始资料，分析了合作的过程，梳理出合作机制。研究发现，在合作中政府从资源整合的角度积极促进学校与社会力量的合作，并把自己的权力转嫁给学校，学校因此在合作前期几乎集中了所有的权力。而政府与学校对于课后服务形式的不同需求，导致学校对多元化的课后服务需求不高。学校的高权力与弱需求一定程度上对合作的达成起消极作用。而合作一旦达成，社会力量依靠自己完善的培训体系与强大的服务沟通能力，在合作中逐渐夺回部分权力，而使合作回到平等状态。社会力量在两期合作中的间歇时期持续解决合作中的问题并积极反馈合作效果，为学校和政府的政绩填色，并顺利的进入下一期合作。但合作中存在各方信息不对称、学生与家长的评价机制缺失、各主体合作目标不统一、对合作内容的认知不同等问题。针对上述问题，本文建议政府在合作中从顶层设计角度制定科学的目标与绩效管理可以使合作主体更加清楚的认识到彼此的责任与义务，综合协调和管理合作中的利益分配、资源整合，建立完善的合作保证机制，促进合作透明、健康、长久的进行下去。

The "double reduction" policy has attracted social attention since its release. For students, the"double reduction" policy aims to reduce their burden, but instead puts forward higher requirements for schools: schools should improve teaching quality, optimize teaching skills,improve homework quality, and comprehensively promote after-school services to solve the"3:30 problem". After class services and regular courses, especially non disciplinary courses and activities, are very challenging for school teachers who have been engaged in subject education for a long time. In this context, a large number of schools are choosing to collaborate with social institutions to provide after-school services. By reviewing the entire cooperation process, analyzing the power and responsibility of each subject, sorting out the driving force and communication mechanism of cooperation, and analyzing the existing problems and difficulties.In the context of open policies, many schools collaborate with social forces to provide after-school services within the framework of government procurement services. This article selects 6 primary schools in S city that cooperate with the same social force. In the early, middle,and late stages of the cooperation, interviews are conducted based on the identity attributes of thecooperating subjects to obtain original data, analyze the process of cooperation, and sort out the cooperation mechanism.Research has found that in cooperation, the government actively promotes cooperation between schools and social forces from the perspective of resource integration, and transfers its own power to schools. As a result, schools almost concentrate all power in the early stages of cooperation. The different needs of the government and schools for after-school services have led to a low demand for diversified after-school services in schools. The high power and weak demand of schools have a negative impact on the achievement of cooperation to some extent.Once the cooperation is achieved, social forces rely on their well-established training system and strong service communication skills to gradually regain some power in the cooperation, and bring the cooperation back to an equal state. During the intermission between the two phases of cooperation, social forces continue to solve problems and actively provide feedback on the effectiveness of the cooperation, adding color to the achievements of the school and government,and smoothly entering the next phase of cooperation. Subjectively, this prolongs the cooperation cycle, which is beneficial for the formation of a trust relationship among the three parties.However, there are problems in cooperation, such as information asymmetry among all parties,lack of evaluation mechanisms between students and parents, inconsistent cooperation goals among various parties, and different understandings of cooperation content.In response to the above issues, this article suggests that the government formulate scientific goals and performance management from the perspective of top-level design in cooperation,which can make the cooperating parties more aware of each other's responsibilities and obligations, comprehensively coordinate and manage the distribution of interests and resource integration in cooperation, establish a sound cooperation guarantee mechanism, and promote transparent, healthy, and long-term cooperation.