An　experimental　test　system　including　the　oil　circulation　system　and　the　gas　circuit　system　has　been　designed　and　built　to　explore　the　effects　of　the　lubricating　oil　flow　rate　on　the　performance　of　a　single-screw　compressor,　used　in　a　portable　natural　gas　liquefaction　process.　Outlet　pressure,　outlet　volumetric　flow　rate,　volumetric　efficiency,　and　specific　power　rate　are　the　parameters　for　evaluation　of　the　energy　performance　of　the　single-screw　compressor.　The　experimental　results　indicate　that　the　outlet　pressure　and　outlet　volumetric　flow　rate　can　be　effectively　increased　by　increasing　the　flow　rate　of　the　lubricating　oil　at　different　rotational　frequencies　and　that　a　certain　amount　of　lubricant　oil　is　helpful　to　improve　the　volumetric　efficiency.　In　terms　of　the　specific　power　rate,　the　optimum　oil-gas　ratios　are　0.7%,　0.93%,　and　1.79%,　and　the　corresponding　outlet　pressures　are　0.45,　0.45,　and　0.48　MPa　at　the　conditions　of　50,　40,　and　30　Hz,　respectively.