In order to obtain high efficiency diode pumped alkali metal vapor laser, a gain cell with Brewster angle structure is used. The one-trip transmittance of the laser is improved effectively and the one-trip transmittance of the laser in p-polarization is 97%. A gain cell with length of 1 nm is used. It is filled with alkali metal rubidium vapor as gain medium and methane with pressure of 79.99 kPa as buffer gas. A diode laser is used as the pump source when the power is 48 W, the central wavelength is 780 nm and the line width is 0.1 nm. In order to reduce the thermal effect of gain cell, a chopper is used to change the continuous pump laser to pulse output with pulse width of 1.85 ms , repetition frequency of 15 Hz and duty ratio of 2.77%. The experiment is optimized by using 12 cm flat concave resonator and the output mirrors with output coupling rate of 41%, 58%, 76%. When the temperature of the cell is 160 ℃, using the output mirror of 76%, the rubidium laser with wavelength of 795 nm and highest peak power of 16.8 W is obtained. The optical to optical efficiency is about 35%, and the slope efficiency is 44.2%.