A method and device for realizing smart antenna in WCDMA system are disclosed in the invention, including array antenna, radio frequency channel module, beam forming module, channel environment detection and classification module, beam-forming algorithm selection and weight value generation module. After processing the signals received by the antenna array in RF channel, the baseband array data X including multiple components is obtained, then the channel environment is estimated and identified according to the characteristics of said array data, and the channel type which the channel belongs to is determined; the corresponding adaptive beam forming algorithm is selected according to the identification result of the channel type, so as to calculate the uplink weight value W including multiple components; said array data X and weight value W are multiplied so as to form beam Y. The invention can adopt corresponding adaptive beam forming algorithm based on the channel environments, thus it can effectively restrain the interference under various channel environments.