The invention provides a method and a communications device for transmitting information. The method includes: determining a quantity N of padding bits according to a quantity M of effective information bits included in a code block and a quantity L of effective input ports of a polar code encoder, where M and L are positive integers, and N is a difference between L and M; determining input bits that are to be input into the polar code encoder, where the input bits include the M effective information bits and the N padding bits; inputting, according to a mapping relationship between the L effective input ports and the input bits, the input bits into the polar code encoder through the L effective input ports to perform coding, so as to obtain coded bits; and transmitting the coded bits. This bit-padding manner has ensured successful information transmission.