The invention discloses a circuit for turning off ground wires to solve gear interference of hall switches. Encoding circuit unit output terminals of an N-gear hall module, an R-gear hall module and a D-gear hall module are connected with an RND-gear output encoding module and an ECU electronic control module. A power supply output terminal of the ECU electronic control module is connected to the RND-gear output encoding module. Ground terminals of hall switches of the R-gear hall module and the D-gear hall module are connected to a controllable ground wire module. A ground terminal of a hall switch unit of an N-gear hall module is connected to the ground. A signal terminal of the hall switch unit of the N-gear hall module is connected to the controllable ground wire module in order to control on-off of the controllable ground wire module. When an AMT gear shifter has R-gear or D-gear interference at an N gear, the controllable ground wire module is enabled by an N-gear hall to turn off ground wires of R-gear and D-gear modules, thereby solving the problem that the AMT gear shifter has R-gear or D-gear interference at the N gear.