Aimed at the problems that the hydration of Portland cement commonly used in pavement repair is tending towards stagnation, and the strength is difficult to generate under severe cold environment (-20 °C),a magnesium phosphate cement is selected which can still hydrate normally under negative temperature environment. The effects of water-cement ratio(W/C), borax content, polycarboxylate superplasticizer content and naphthalene superplasticizer content on the early performance of magnesium phosphate cement in severe cold environment are studied, and the optimal ratio is given. The results show that the increase of W/C in cold environment enables to reduce the flexural strength and prolong the condensation time, but has little effect on the compressive strength. The borax dosage and strength basically show a trend of increasing first and then decreasing, and the strength performance is better at 5%. With the increaseof polycarboxylate superplasticizer, the compressive strength shows a trend of increasing first and then decreasing. And the flexural strength shows the same law at 1 h, and then shows a negative correlation at the later stage. The content of naphthalene superplasticizer is negatively correlated with strength. Therefore, this paper recommendes to choose the mix ratio of 0.16 W/C, 5% borax dosing and 0.4% polycarboxylate superplasticizer dosing in the cold environment. The results of this paper can provide a theoretical support for the rapid repair of airport pavement in the severe cold environment.