In order to improve the output frequency stability of 1 083 nm distributed Bragg reflector (DBR) laser for high-sensitivity ⁴He magnetometer,we propose a new polarization heterodyne saturated absorption spectroscopy (PHSAS) technique based on the D₀ line of ⁴He atoms,which obtains a frequency discrimination curve from the differential signal of the saturated absorption spectra of metastable helium atoms in two mutually perpendicular polarization directions.Theoretical calculations show that this spectral technique can increase the amplitude of the resonant signal by 50%,while completely eliminating the influence of Doppler background near resonance and suppressing the common-mode noise of the laser,thereby improving the frequency stability of the laser controlled by conventional saturated absorption spectroscopy (SAS).In comparison with SAS used for laser frequency stabilization control,our experiment demonstrates that the proposed method can increase spectral amplitude by 20% and achieve an Allan deviation of 6.9×10-10@10 s,which is a five-fold reduction.Considering the influence of the experimental environment,the results have verified the theoretical expectations.