Hydraulic support tester is the key equipment to measure the safety performance and technical performance of the hydraulic support. As an integral part of hydraulic support tester, synchronized loading system bears much load and eccentric load, needs high synchronization precision, and exits mechanical-hydraulic coupling. For these characteristics, building a synchronous loading system platform model, carrying on force analysis of the platform, and then getting four-cylinder pressure at different heights of the loading course are necessary. This research constructs a synchronous control circuit for hydraulic loading system using multi-physic modeling and simulation software—AMESim; simulation is carried out to optimize parameters of PID controllers in order to reduce the four-cylinder position synchronization error. As a conclusion, simulation results validate that appropriate solutions improve the precision and also demonstrate that the designed control system is suit for the synchronization control of the four-cylinder.