Chinese image caption， In the result, multiple words of the same type appear

Hello, I am using the COCO dataset,
A two-layer LSTM model, one layer for top-down attention, and one layer for language models.

Extracting words with jieba
I used all the words in the picture description that occurred more than 3 times as a dictionary file, and a total of 14,226 words.
words = [w for w in word_freq.keys () if word_freq [w]> 3]

After training the model, when using it, multiple words of the same type appear in the result, such as:

Note notebook laptop computer on bed
A little girl little girl girl standing together

How can I solve this problem?