A sowing device changes a depth of wheat sowing includes an external skeleton, where one side of the external skeleton is fixedly connected with a connection part for articulated with a tractor; a main board slidably connected to an interior of the external skeleton and a seeding unit below the main board; a support frame fixedly connected to the main board; a plow blade for slotting land rotatably connected to a bottom of the support frame; a rotary roller below the external skeleton and rotationally connected thereto. The main board is moved downwards to drive a straight toothed plate fixedly connected to the main board to move downwards; the straight toothed plate is moved upwards through a meshing effect of a gear to cause L-shaped toothed plate to move upwards to squeeze a horizontal plate to move upwards.