在春节用in用on都可以，in the Spring Festival指在春节期间，on the Spring Festival指的是在春节那一天。

在春节用什么

at Spring Festival：在春节期间（注意不只一天）

in the Spring Festival：指在春节期间

on the Spring Festival：指在春节那一天

during the Spring Festival：春节期间

the Spring Festival：春节

Spring Festival例句

The Spring Festival is only a week away.

离春节只有一周了。

The Spring Festival is drawing near.

春节快到了。

The shops are very busy before the Spring Festival.

春节前商店里十分繁忙。

The Spring Festival is the lunar New Year.

春节即农历新年。

He'll be home for the Spring Festival.

他今年回家过年。