Abstract: Currently,methods for the linear-encoder's static error measurement are relatively mature but not the dynamic's error measurement. This paper presents a dynamic error measurement system to solve this problem. The system consists of mechanical system,control and measurement system,and software,and measurement can be accomplished by comparing with high precision linear-encoder. Driven by a linear motor,the demand of the speed was met,and the efficiency was improved. Bi-channel data acquisition card designed by FPGA could complete the measurement of the linear encoder signal,and solve the high speed sampling problems in the measurement. The result of experiments shows that the system can achieve the measurement of dynamic error for linear-encoders with a high efficiency,which is suitable for measurements in the factory.