The work aims to improve the wear resistance of polyurethane (PU) rubber. Diamond-like carbon (DLC) films were deposited on the pretreated PU rubbers through cathodic discharge plasma method with tetrachloroethylene as soluble plastic agent. Scanning electron microscopy and Raman spectroscopy were taken to observe and characterize the surface morphologies and compositions of the deposited films, respectively. The tribological behavior of specimens was investigated with friction testing machine under dry sliding condition and wear morphology was observed. The depth of original stripes on the substrate surface increased firstly and then decreased with the increase of temperature and time of ultrasonic treatment of tetrachloroethylene. The surface of the coated specimen was flat and the roughness decreased gradually. With the increase of ultrasonic treatment temperature and time, the coating composition changed from amorphous carbon structure to typical diamond-like structure with diamond phase mixed with graphite phase. The coefficients of friction (CoF) of coated rubbers were 40% lower than that of uncoated rubber under dry friction. With the increase of temperature and time of ultrasonic treatment under dry friction, the friction coefficient and wear amount of coated specimen firstly decreased and then increased. Specifically, both of the CoF and mass loss of coated specimen 4 were the smallest after treatment for 15 min with tetrachloroethylene at 50 ℃. The ultrasonic treatment with tetrachloroethylene can improve the wear resistance of DLC films deposited on PU rubbers. The most suitable temperature and time of ultrasonic treatment with tetrachloroethylene are 50 ℃ and 15 minutes.