A tunable external cavity laser with dual gain chips, including: a polarization beam splitter having a beam splitting surface arranged at an angle of 45° with respect to a first direction and a second direction perpendicular to the first direction; a first gain chip arranged in the first direction; a second gain chip arranged in the second direction; a feedback cavity arranged in the first direction, wherein the feedback cavity and the first gain chip are respectively arranged on two opposite sides of the polarization beam splitter, and the feedback cavity includes at least one independent Fabry-Perot etalon, at least one air gap Fabry-Perot cavity and a mirror that are arranged in the first direction. The polarization beam splitter and the two gain chips cooperate to share the feedback cavity, so that a wavelength and a phase may be adjusted, and a larger tuning range may be obtained.