A novel worm wheel transmission error measurement system based on a new space-time subdivision technology is presented in this paper. Non-integer transmission ratio with high precision can be measured with this measurement system. FPGA chip is employed to meet the requirement of high precision and real-time, and USB2.0 meet the requirement of high speed data acquisition and real time data transmission. In addition, precision self-checking is studied with quantitative shifting method, and the experiment method on repeatability test and data processing are studied with dual-observation method. Experiment results prove that this measurement system has high precision and good repeatability.