We investigate 750nm and 532nm dual-wavelength laser for applications in the inteet of things.A kind of optical maser is developed,in which the semiconductor module outputs the 808 nm pump light and then it goes into a double-clad Nd3+ ∶YAG monocrystal optical fiber through the intermediate coupler and forms a 1064nm laser.The laser outputs come from both left and right terminals.In the right branch,the laser goes into the right cycle polarization LinNbO3 (PPLN) crystal through the right coupler,produces the optical parametric oscillation and forms the signal light λ1 (1500hm),the idle frequency light λ2 (3660.55nm),and the secondharmonic of the signal light λ3 (750nm).These three kinds of light and the pump light λ4 together form the frequency matching and the quasi-phase matching,then the four-wave mixing occurs to create the high-gain light at wavelength 750nm.Meanwhile,in the left branch,the laser goes into the left PPLN crystal through the left coupler,engenders frequency doubling and forms the light at wavelength 532nm.That is to say,the optical maser provides 750 nm and 532 nm dual-wavelength laser outputting from two terminals,which is workable.