The invention relates to a multifunctional ultrahigh-frequency partial discharge sensing device. The device comprises a shell, a first output port, a second output port, a signal coupler, a change-over switch and a signal conditioner, wherein the first output port and the second output port are arranged on the shell, the signal coupler, the change-over switch and the signal conditioner are installed in the shell, the signal coupler is used for acquiring ultrahigh-frequency partial discharge signals of high-voltage electrical equipment so as to obtain acquired signals, the change-over switch isconnected with the signal coupler, and is used for transmitting the acquired signals acquired by the signal coupler to the first output port or to the signal conditioner, and the signal conditioner is connected with the change-over switch and is used for receiving the acquired signals transmitted by the change-over switch, filtering and amplifying the acquired signals and then transmitting the acquired signals to the second output port. The device is convenient to carry, moreover, the effect that the same device can be applied to different types of detectors can be achieved, the working process is simplified, the operation risk is reduced, and the working efficiency is improved.