The successive cancellation list (SCL) decoding algorithm of polar code is of bitwise, which is the main source of the decoding complexity and latency. In view of the analysis of the advantages and disadvantages of the existing SCL and multi-bit decision decoding, each set of multi-bit code words (multiple independent channels) is treated as a whole to construct a multi-bit virtual channel, which can transmit multi-bit code words and decode synchronously. Therefore a construction of multi-bit virtual channel based on the SCL algorithm under the AWGN channel is proposed to against the problem of high complexity and large delay for decoding system caused by SCL decoding. It is also enhanced by combining with the establishment threshold of the decoder tree nodes to reduce the number of tree nodes' split. Under the AWGN channel, the bit error rate and the frame error rate performance of the virtual 2, 4 and 8 bit channels are simulated. The simulation results show that the decoding performance is close to that of the traditional SCL algorithm when the default threshold S=30 in the case of a virtual 8-bit channel. The total number of nodes is reduced by 63.7% and the total number of additions is 17% of the 8-bit decision decoding algorithm. The proposed algorithm can effectively reduce the calculation complexity of decoding and the hardware storage. It is more suitable for hardware implementation and has a certain practical value.