The invention relates to a lamp holder fixing device, which comprises an inverted Z-shaped fixing clamp and a lamp holder support, wherein the inverted Z-shaped fixing clamp is used for clamping a fixing position, and the lamp holder support is used for fixing a light source component and is connected with the fixing clamp. A clamping portion and a connecting portion on the fixing clamp are arranged on two opposite planes of the inverted Z-shaped fixing clamp respectively, wherein the clamping portion is used for clamping the fixing position, and the connecting portion is used for connecting the inverted Z-shaped fixing clamp with the lamp holder support. A lamp holder is connected onto the lamp holder support, and the fixing clamp is fixed to a helmet in a clamping manner, so that the lamp holder can be conveniently, rapidly and detachably assembled with the helmet. When not needed, the lamp holder can be simply and rapidly detached without an external tool, the helmet is kept balanced, a wearer can comfortably and stably wear the helmet without affecting normal operation, great convenience is brought for the wearer, and the burden of the wearer is greatly relieved. Besides, a clamping antislip pad is arranged between an upper clamping piece and a lower clamping piece, so that the fixing clamp can be stably clamped on the helmet without sliding and shaking, and use is further facilitated for the wearer.