Engine cylinder lossless detection device

The invention discloses an engine cylinder lossless detection device which comprises a supporting mechanism, a sliding block, a spring seat, a telescopic rod, a probe and an encoder. The supporting mechanism is fixed on a cylinder opening of an engine, the sliding block is arranged on the supporting mechanism and can move relative to the supporting mechanism in a rotating mode, the spring seat is arranged on the sliding block and connected with the sliding block in a sliding mode, the spring seat can move forwards relative to the horizontal direction of the sliding block, the telescopic rod is arranged on the spring seat in a penetrating mode and can move forwards in the vertical direction relative to the spring seat, the telescopic rod penetrates through the supporting mechanism, and one end of the telescopic rod is accommodated in an engine cylinder. The probe is detachably arranged on the telescopic rod, the detection end of the probe is accommodated in the engine cylinder, and the probe is electrically co