The effect of low-temperature hardening with tray overlapping on the quality of seedling in film overlay and open-air seedling raising was explored with the early rice variety Zhongjiazao 17 as the experimental material. The results showed that under open-air seedling raising condition, compared to the treatment without low-temperature hardening, the seedling rate of low-temperature hardening treatment increased by 8.8%, and the seedling quality was also higher, the chlorophyll content of seedlings of open-air seedling raising 15 d and 30 d treatments increased 8.7% and 37.1%, the dry weight increased 23.2% and 12.5%, and the seedling fullness increased 15.5% and 6.9%, respectively. Under the condition of film overlay raising, compared with no low-temperature hardening, the effect of low-temperature hardening on the seedling rate was not significant, but the chlorophyll content and dry matter accumulation of the seedlings showed a downward trend. The results provide technical reference for early rice seedling rasing to alleviate low-temperature damage.