Aiming at shortcomings of the existing electronic power steering（ EPS） torque sensor are easily affected by noise

and power supply is difficult

combined with characteristics of high sensitivity and strong anti-interference ability of surface acoustic wave（ SAW） device a steering torque measurement method is put forward according to the principle of SAW. Based on the characteristics of complex environment and large temperature variation of vehicle-mounted EPS

a structural design scheme of SAW torque sensor for EPS is proposed

which can eliminate temperature effects. In signal processing

aiming to the M-Rife algorithm in frequency estimation

the total of estimation results will occur frequency offset and the error is too large

a new algorithm of improved M-Rife algorithm based on Welch and iterative interpolation（ IIN） algorithms is proposed. Simulation and test results show that the improved algorithm has better precision in estimation of SAW torque sensor frequency signal for EPS

it is prior to that while the M-Rife algorithm is simply used.