The invention discloses a protector for ultrasonic probes. The protector comprises a probe fixing device, probe fixing trays, protection and detection wedge blocks and an instrument cabin housing, wherein the front end of the probe fixing device is in threaded connection with a drill collar; the rear part conical cylinder of the probe fixing device is connected with the instrument cabin housing; through holes are formed in the middle cylinder body of the probe fixing device; the probe fixing trays are mounted in the through holes; the protection and detection wedge blocks are fixed on the probe fixing trays; and ultrasonic probes are fixed on the protection and detection wedge blocks. Therefore, the technical problem in the prior art that the ultrasonic probes are completely impacted by gravel in boreholes when used for detecting the directional boreholes is solved, the ultrasonic probes can realize quality detection of aperture sizes, hole wall collapse conditions and hole wall shapes, the on-site detection reliability is further guaranteed, the ultrasonic probes are protected against damage, scientific references are provided for crossing construction of directional drilling, successful construction of pipeline crossing is guided, and the crossing risk is reduced.