In the progress of servo testing, the actual servo-angle signal is needed to be acquired for the calibration and performance evaluation of the servo system. The traditional servo-angle acquisition system is composed of PCI-based acquisition board and IPC, which has high-cost and needs special computer. For the requirement of a low-cost and universal servo-angle acquisition system in servo testing, a lower computer based on STM32F103 is designed to instead of traditional PCI-based acquisition board. The lower computer communicates with PC via USB interface. The PC software based on LabWindows/CVI is designed for communication and human-computer interaction. This system features low-cost,high reliability,high flexibility,and it has been successfully applied in servo testing. The experiment results demonstrate the outstanding achievement of the system.