Abstract: In order to study the conditions for the recycling of concrete damaged by freezing and thawing, and to promote the application of recycled aggregates in cold areas in practical projects, this paper used C30 concrete as a benchmark to discuss the gradation form, the replacement rate of recycled aggregates, the amount of superplasticizer and the influence of sand rate on the compressive strength of recycled concrete, and the mechanical properties of recycled concrete from old bridges that had been in service for 28 years in cold areas and recycled concrete from old test blocks in the laboratory were analyzed. The test results showed that: continuous gradation should be used in the design of recycled aggregate concrete mix ratio; increasing the replacement rate of recycled aggregate and sand ratio had a negative impact on the compressive strength of recycled concrete; superplasticizer could effectively improve the mechanical properties of recycled concrete; when the replacement rate of recycled aggregate was the same, the 28-day compressive strength of recycled aggregate concrete of the old bridge was 17.05% lower than that of recycled concrete of the old test block. When using recycled aggregate in cold areas, attention should be paid to controlling the replacement rate.