The master oscillator power amplifier （MOPA） laser is receiving increasing attention due to its ability to achieve high power and beam quality output. In order to improve the polarization degree of MOPA laser and reduce the efficiency loss during polarization combining， InGaAs/AlGaAs compressive single quantum well was used in the active region. The optical confinement factor of TE-mode in ridge waveguide was improved by 1.35 μm deep etching， whereas the TE optical gain in tapered amplifier was increased through on-chip metal stress regulation. Combining the two schemes not only improves the degrees of polarization （DOP） of two sections， but also reduces the polarization angle difference. Finally， 11 W@15 A continuous output and over 90% DOP of the MOPA have been achieved by standard process fabrication.