To against the backdrop of volume fracturing in tight oil formations，the study aimed to precisely regulate the degradation reaction of slickwater in distal micron sized or nano-sized fractures using ammonium persulfate（APS）as a breaker. It focused on the influencing factors in the construction and release control of thermal-controlled APS nanocapsule breakers. Using poly（methyl methacrylate）（PMMA），dichloromethane（DCM），Span 80，cyclohexane（CYH），triblock copolymer（Pluronic P-123）and APS as raw materials，APS droplets were encapsulated through the interfacial chemical action of hydrophobic polymer wall materials in a W/O inverse microemulsion，forming nanocapsule breakers. The preparation conditions for the nanocapsule breakers were optimized，and then the mechanism of controlled APS release and partially hydrolyzed polyacrylamide（HPAM）degradation by thermal-controlled nanocapsule breakers was analyzed by measuring the APS release rate at different temperatures and the viscosity retention rate of HPAM in simulated slickwater. The results showed that the optimum preparation condition of nanocapsule breakers was obtained as follows：50 ℃ reaction temperature，1∶1.5 volume ratio of DCM and CYH，100 mg Pluronic P-123，200 mg PMMA，10% mass fraction of APS in the core material，and 1∶1 volume ratio of Span 80 and APS solution. The nanocapsule breakers had an average particle size of 221 nm，good sphericity，and a theoretical shell thickness of 13 nm，with an APS loading rate of 78%. By utilizing the oxidative degradation characteristics of APS on the temperature-sensitive surfactant Pluronic P-123 at specific temperatures（60—80 ℃），a“thermal control switch”for the nanocapsule shell was preset，enabling precise regulation of APS release. The degradation times for HPAM in slickwater at 60 ℃ and 80 ℃ were 24 hours and 12 hours，respectively. The research findings provided a new approach to addressing the bottleneck of degradation and removal of slickwater residue blockages in complex fracture networks，especially in the distal secondary micro-fracture systems of horizontal wells undergoing volume fracturing in tight oil formations.