Wireless transmission being open in channel and broadcast in signals, there is a possibility to make legal users eavesdropped by illegal users in serving. In view of this question, the source code blocks are encoded with random linear network coding technology as inner codes in combination with network coding and polar-code technologies. Depending on Bhattacharyya-parameters, the channels are classified and the secure bit-channels are selected to structure secure a polar-code as outer codes to transmit internal codes, and a scheme of channel coding is adopted， carrying out concatenation of outer codes and inner codes. The simulation results show that when the SNR of the main channel is 10 dB, both of the proposed method and the traditional secure polar-code method can provide reliable communication service for the legitimate receiver. With this method adopting 8 bit finite field,only by degrading into 2.5 dB for the SNR of the eavesdropping channels can the block error rate of the eavesdropping channel approximate to 1,whereas the traditional polarization code method requires that the SNR of the eavesdropping channel degrades by 4 dB. Compared with the traditional method, the proposed method can further resist eavesdropping transmission.