Sentiment analysis is a process of detecting sentiment through texts. It has become a very popular research work in natural language processing. Maximum researchers work with social media texts, tweets, and reviews. In this paper, we are working with Bangla text for child sentiment analysis. Child sentiment means a child's emotion which can be positive, negative, and neutral. Child sentiment analysis is needed for future development in psychology which will help researchers to detect a child's sentiment. This research paper will help to detect a child's positive, negative and neutral sentiments. To build this model we apply many machine learning and deep learning algorithms. The BERT model gives the best accuracy for our data set which is a deep learning model and MNB gives the highest accuracy from machine learning algorithms.