Qingguang Park is a tiny, but very busy park. In the evening this park is usually full of children playing on the nearby playground, people exercising on the equipment, and others having a snack from Shuangcheng market just down the street. The street market is open 24 hours, so they'll always have something if you're a bit hungry after your search.
The cache is somewhat out of the way of the really busy parts of the park, but some stealth is definitely required. You're more likely to run into one of the many neighborhood cats that call the park home.