The invention provides a lead wire sealing device of a sensor. The lead wire sealing device comprises a casing and a sealing structure, wherein the casing is used for accommodating a model; the sealing structure is arranged at the outer side of the casing; the casing wall of the casing is pre-formed with at least one first lead wire interface; the sealing structure comprises a first sealing sleeve cylinder, the first sealing sleeve cylinder is arranged in the first lead wire interface, a lead wire of the sensor penetrates through the first sealing sleeve cylinder and is led out of the casing, and a first sealing layer is arranged between the first sealing sleeve cylinder and the lead wire of the sensor; a first sealing part is fixedly sheathed at one end, in the casing, of the first sealing sleeve cylinder, and a second sealing part is fixedly sheathed at one end, outside the casing, of the first sealing sleeve cylinder; through holes are respectively formed in the first sealing part and the second sealing part, and the size of the cross section of each through hole is smaller than the first lead wire interface. The lead wire sealing device has the advantage that in the testing process, even if the casing wall produces a gap with the first sleeve cylinder due to stress deformation, the gap can also be blocked by the first sealing part and the second sealing part, so that the sealing property is good, and the simulation result is more accurate.