Injector capable of automatically separating needle head

The utility model provides an injector capable of automatically separating a needle head. Injector comprising an injector body, wherein the injector body comprises an injector shell; a pressing shell is fixed on the outer wall of the injector shell; a first pressing rod, a second pressing rod and a third pressing rod are installed in the pressing shell, the first pressing rod and the third pressing rod are connected to the two ends of the second pressing rod, the first pressing rod extends out of the upper end of the pressing shell, and the third pressing rod extends out of the lower end of the pressing shell. A pressing plate is arranged at the upper end of the pressing rod I, and the lower end of the pressing rod III is connected with an elastic sheet; the elastic piece is arranged on a needle head connecting part located at the lower end of the injector shell in a sleeving mode, and a spring is arranged on the periphery of the third pressing rod. By using the needle head separating device, the needle head