The invention discloses a waterproof projection lamp with high heat conductivity. The waterproof projection lamp with high heat conductivity comprises a lamp body main body, a power supply box and a support, wherein the lamp body main body, the power supply box and the support are used for illumination, the power supply box comprises a power supply cover, a power supply cover silicone pad used forwaterproof is arranged at the power supply cover, the power supply box and the support are arranged on the lamp body main body, and the lamp body main body comprises an LED lamp bead, a light reflection cup and a fixed silicone pad, wherein the LED lamp bead, the light reflection cup and a fixed silicone pad are arranged in an installation position of the lamp body main body in sequence, and thefixed silicone pad has functions of fixation, water resistance and corrosion prevention at the same time; a right-angle silicone pad is arranged in the installation position, the parallel part of theright-angle silicone pad is arranged on the edge of the light outlet position of the light reflection cup, so that the light reflection cup can be further fixed, and meanwhile, the waterproof performance is better; and a lamp body rear cover of the lamp body main body is designed into a scallop-type structure with a good heat dissipation effect, and furthermore, a water outlet small hole enablingrainwater to flow out is formed in the installation position, corresponding to the fixed silicone pad, of the lamp body rear cover. According to the waterproof projection lamp with high heat conductivity, the waterproof effect and the heat dissipation effect are good.