nm/780 nm double wavelength multiquantum well(MQW) lasers combined by GaAs tunnel junction were designed through simulation and previous experiment data.The parts of 650 nm/780 nm multiquantum well active regions were simulated by computer.Lasers' transverse mode characteristic,near field distribution and far field angle were calculated.The lateral mode of lasers with refractive index structure were qualitative analyzed,the conditions of perfect lateral mode were found.