The characteristics of curved semiconductor nanowire (NW) lasers were investigated. The red-shift in the laser spectra with increasing bending angles can be observed much more clearly than that in the photoluminescence (PL) spectra. Due to oscillation of light in resonant cavity, the bending loss of laser exhibits multiple times amplification of that of PL. Furthermore, an abnormal phenomenon of dominant peak switching is found in curved NWs when increasing the pump power, which has been first discovered and reported.