The invention relates to a wearing-resistant ultrasonic thickness meter with high testing precision. The ultrasonic thickness meter comprises a host machine, a connecting line, an operating lever, a flat plate, a testing mechanism and two fixing mechanisms. The fixing mechanism comprises a fixed plate, a first motor, clamping plates and two telescopic assemblies. The telescopic assembly comprisesa bearing, a first driving shaft, a moving block, a telescopic rack and two first connecting rods. The testing mechanism comprises a moving assembly, a movable board, a second motor, a turntable and two testing assemblies. The testing assembly comprises an adjusting unit, an adjusting plate, a probe and a plurality of testing units. The wearing-resistant ultrasonic thickness meter with high testing precision makes the two clamping plates fix a workpiece through the fixing mechanisms, thereby preventing relatively large-distance offset of a probe in a testing process, and ensuring smooth testing. Furthermore, in a process of driving the probe to perform rotating testing through the testing mechanism, the angle of the probe is adjusted and testing precision is improved; and furthermore wearing caused by contact between the probe and the workpiece is prevented, thereby prolonging service life of the equipment.