Semiconductor laser chips with 976 nm wavelength, broad stripe and high power are designed and realized. The epitaxial structure design of an asymmetric and large waveguide, and metal organic chemical vapor phase epitaxy technology are used to grow epitaxial materials with low loss and high conversion efficiency. The semiconductor laser chips with 190 μm stripe width, 4 mm length and 976 nm wavelength are packaged and packaged as chip-on-submount. The test results show that the threshold current of package-device at room temperature is 1.05 A, slope efficiency is 1.12 W/A, and the maximum conversion efficiency is 68.5%. Even at the elevated temperature of 40 ℃ and the output power of 19.5 W, the conversion efficiency reaches 60%. Nine devices are aging-tested at 40 ℃ and 15 A for 4740 hours, and no failure occurs. There are no changes in power-current curves and spectra before and after aging-test, which proves high stability and reliability of the laser chips.