Spraying WC10Co4Cr coatings by HVOF on typical aerial material TC18 Alloy is one of most important method to improve its wear. In this paper, oxygen flow rate, kerosene, spray distance and powder feed rate were as main parameters and L9_3_4 orthogonal experiments were set up. Comparing with influences of parameters on porosity and W₂C content each other, optimized parameters were found. The optimized parameter is as follows: O₂, 873NLPM, Kerosene, 22LPH, Spray distance, 380mm, powder feed rate, 60g/min. The optimized WC10Co4Cr coatings’ performance is as follows: its porosity is less than 1%, its micro-hardness is HV_0.31204.8, its bonding strength is 74.5MPa, no spalling after bending test. All of these have met with AMS 2447 standard. Under the test conditions, the wear of WC10Co4Cr coatings is 3.371×10_-7mm₃/ N.m and that of TC18 is 3.371×10_-7 2.095×10_-3mm₃/Nm. The wear resistance of TC18 was improved greatly.