A message sending method, comprising: generating, by a base station, a scrambling code according to a first time parameter, wherein the first time parameter is equal to a value resulting from a radio frame number modulo a first modulus, and the first modulus is a positive integer; scrambling, by the base station, a system message according to the scrambling code; and sending, by the base station, the scrambled system message to a terminal on a physical broadcast channel, wherein the generating, by the base station, the scrambling code according to the first time parameter comprises: generating, by the base station, a scrambling code initialization seed according to the first time parameter and a first variable group, or according to the first time parameter, wherein the first variable group comprises at least one of a cell identity, a radio network temporary identifier, RNTI, and a carrier identifier, wherein the scrambling code initialization seed c init meets the following expression: c init = P · n ƒ mod8 + 1 3 · 2 a 3 + N ID cell, wherein P is a function of the cell identity, n f is the radio frame number, a 3 is a non-negative integer, and N ID cell is the cell identity; and generating, by the base station, the scrambling code according to the scrambling code initialization seed. generating, by a base station, a scrambling code according to a first time parameter, wherein the first time parameter is equal to a value resulting from a radio frame number modulo a first modulus, and the first modulus is a positive integer; scrambling, by the base station, a system message according to the scrambling code; and sending, by the base station, the scrambled system message to a terminal on a physical broadcast channel, wherein the generating, by the base station, the scrambling code according to the first time parameter comprises: generating, by the base station, a scrambling code initialization seed according to the first time parameter and a first variable group, or according to the first time parameter, wherein the first variable group comprises at least one of a cell identity, a radio network temporary identifier, RNTI, and a carrier identifier, wherein the scrambling code initialization seed c init meets the following expression: c init = P · n ƒ mod8 + 1 3 · 2 a 3 + N ID cell, wherein P is a function of the cell identity, n f is the radio frame number, a 3 is a non-negative integer, and N ID cell is the cell identity; and generating, by the base station, the scrambling code according to the scrambling code initialization seed. generating, by the base station, a scrambling code initialization seed according to the first time parameter and a first variable group, or according to the first time parameter, wherein the first variable group comprises at least one of a cell identity, a radio network temporary identifier, RNTI, and a carrier identifier, wherein the scrambling code initialization seed c init meets the following expression: c init = P · n ƒ mod8 + 1 3 · 2 a 3 + N ID cell, wherein P is a function of the cell identity, n f is the radio frame number, a 3 is a non-negative integer, and N ID cell is the cell identity; and generating, by the base station, the scrambling code according to the scrambling code initialization seed.