The research project has participatedin the "2020 Social Practice and Science Competition on Energy Conservation and Emission Reduction for College Students" and won the second prize.这句话中，second prize前是否需要加the

Yes, it is grammatically correct to include "the" before "second prize" in the sentence. Therefore, the sentence can be written as:

The research project has participated in the "2020 Social Practice and Science Competition on Energy Conservation and Emission Reduction for College Students" and won the second prize.