Problem about KL loss when training CVAE model.

When I trained CVAE on my own dataset, I found that the results were very poor. Upon inspection, I found that the KL loss is too large at training and validation time, reaching around 10^27, and will not decrease. A closer look shows that the encoder output `log_var` is 50~60. I have been adjusting for a long time without effect. How to solve this situation?