Construction system of user portrait model

The invention discloses a system for constructing a user portrait model, and the system comprises a data collection module which is used for obtaining the historical data of a to-be-analyzed user through a bag-of-words model; the feature construction module is used for constructing a user feature library based on historical data; the feature extraction module is used for performing feature extraction on the user feature library to obtain a user key feature sub-library; the feature selection module is used for carrying out dimensionality reduction on the user key feature sub-library, determining an index tag of the user key feature sub-library and generating a user portrait tag library; the model determination module is used for training a user portrait label library based on a neural network algorithm; and training the index tag of the training data of each time interval according to the weight values of the training data of the plurality of time intervals to obtain a user portrait model. According to the met