Abstract: The reciprocating wear test of 13Cr-L80 steel tubing and casing was carried out with a reciprocating friction and wear testing machine. The effects of contact load (50,100,150,200,250 N), reciprocating stroke (2,4,6,8,10 mm), reciprocating frequency (0.6, 0.9, 1.2, 1.5 1.8 Hz) and completion fluid density (1.0, 1.1, 1.2, 1.3, 1.4 g·cm^-3) on the wear performance of the tubing were studied. The results show that with increasing contact load, reciprocating frequency and reciprocating stroke, the wear amount of the tubing increased, and the friction factor and wear rate changed little. With increasing completion fluid density, the wear amount and wear rate of the tubing decreased, and the friction factor decreased first, and then tended to be stable when the completion fluid density increased to 1.2 g ·cm^-3. Under testing conditions, with increasing contact load, reciprocating frequency and completion fluid density, the wear mode of the tubing changed from the abrasive wear to the adhesive wear, and the wear modes of the tubing under different reciprocating stroke were all adhesive wear.