The invention discloses a lithium battery cap assembling machine for achieving feeding by adopting a bidirectional negative pressure principle. The lithium battery cap assembling machine structurallycomprises an assembling main machine, a processing bin, a controller, a connecting bridge, a feeding device and an electric control cabinet, the bottom of the feeding device is arranged at the top ofthe electric control cabinet in a buckling manner, the electric control cabinet is located at the right side of the assembling main machine, the processing bin is arranged at the top of the assemblingmain machine, and an integrated structure is formed. When a lithium battery is led out, the lithium battery makes contact a universal half buckle and pushes the universal half buckle to be reverselyrotated by one circle and fixed to a fixed half buckle, therefore, guide-out position is positioned, at the moment, a lifting spray head is used for upward driving, finally runway groove guide is carried out through a lateral spray head, a slope guide rail can drive a rise-fall pin to life the lithium battery during lifting, the guide-out speed is improved, through whole use, rapid discharge of the lithium battery can be ensured, the disc clamping phenomenon is not likely to occur, and the rotating disc switching frequency and smoothness are ensured.