In current piezoelectric four-dimensional force measurement methods， torque is determined through two approaches： calculation based on lateral forces or direct measurement. The calculation method offers broad applicability but is significantly affected by cross-coupling between force components， while direct measurement theoretically achieves higher accuracy but is constrained by sensor arrangement limitations. This paper proposed a novel four-dimensional force measurement solution that enabled direct torque measurement without relying on specialized sensor configurations by incorporating quartz crystal sets within the sensor. First， the sensor layout scheme was determined. Based on the existing three-axis force measurement， additional shear force measurement crystal groups were incorporated into each sensor to measure torque. The errors in sensor machining and assembly processes were defined， and a torque measurement error transmission model was established for both measurement methods. A numerical simulation was conducted to compare the accuracy differences between the two methods. A force measuring instrument was designed and fabricated， and the key dimensions of the instrument were analyzed parametrically. Static and dynamic performance calibration experiments were carried out， followed by a multi-point torque loading calibration experiment， in which torque was calculated using both measurement schemes. Experimental results show that the maximum nonlinearity error and repeatability error of the force measuring instrument are both less than 0.5%， the inter-axis interference is less than 3%， and the natural frequency of each axis exceeds 1 400 Hz， meeting the design requirements for static and dynamic performance. In the multi-point torque loading experiment， the root mean square error of the new scheme is reduced by 83.4%， and the maximum measurement error is reduced by 26.5%. These results verify the effectiveness of the new scheme in improving torque measurement accuracy， demonstrating its broad application potential.