A computer input device with switchable operation modes includes a body, a printed-circuit-board (PCB), a processor, and two switches. Two function buttons are disposed on the body to be pressed to move back and forth; the PCB is disposed in the body; the processor and the switches are disposed on the PCB and electrically connected with each other. The processor outputs control signals corresponding to a first operation mode or a second operation mode to a computer. While the switches are respectively triggered by the pressing of the function buttons, triggering signals are transmitted to the processor simultaneously, so that the processor switches the first operation mode to the second operation mode; or the processor switches the second operation mode to the first operation mode.