Atomic layer plasma treatment (ALPT) enhances the corrosion protection of the ZrO2 film prepared by thermal-driven ALD mode (TALD-ZrO2) and further reduces the corrosion rate of MgCa alloy by more than an order of magnitude. The ALPT effect significantly increases the crystallinity and reduces the oxygen defects of TALD-ZrO2 film. The ALPT time of 30 s has the most increase in the polarization resistance of TALD-ZrO2 film, from 1.8kΩ·cm2 to 74.7kΩ·cm2. The enhancement of corrosion resistance of TALD-ZrO2 film caused by the 30s-ALPT is equivalent to the thickness effect of increasing the thickness from 200 cycles to 300 cycles. ALPT technique is considered as a potential and feasible method to prepare TALD-ZrO2 films with high film quality and excellent corrosion protection. •ALPT effectively enhances the corrosion protection performance of TALD-ZrO2 film on Mg-Ca alloy.•Clarify that ALPT technique effectively improves the quality of the TALD-ZrO2 films.•30s-ALPT greatly enhances the polarization resistance from 1.8kΩ·cm2 to 74.7kΩ·cm2.•Clarify that ALPT significantly improves the long-term protection performance of TALD-ZrO2 film on Mg-Ca alloy.