A voltage-force-strain conversion novel high voltage sensor is designed by combining the piezoelectric ceramic actuator with a cantilever beam strain transducer through a longitudinal-bending conversion mechanical structure. The piezoelectric ceramic actuator is T-connected with the elastic cantilever beam structure to form the longitudinal-bending conversion structure, which converts the longitudinal stress/ strain generated by the piezoelectric actuator under the action of voltage into the bending stress/ strain of the cantilever beam, and the longitudinal-bending conversion of stress/ strain is realized. Four resistive strain gauges are placed on the upper and lower sides of the cantilever beam to form a Wheatstone bridge circuit and the bending stress/ strain of cantilever beam is measured. The mechanical conversion design between the strong electricity side of the high voltage and the weak electricity side of the force sensitive ensures a high degree of electrical isolation. The physical model of voltage-force-strain conversion of the sensor is established and verified by finite element simulation. The prototype device is fabricated, and the test results show that the measurement range of the sensor is 0~ 5 000 V, the sensitivity is 0. 01 μV/ V, the nonlinearity error is 1. 83%, and the resolution is 30 V.