A sidelink information transmission method, comprising: Sending, by a network device, first indication information to a first communications device, wherein the first indication information indicates a first resource, the first resource is a resource set used to transmit sidelink information, and the sidelink information comprises sidelink control information and sidelink data; the first resource comprises at least one time unit in time domain and at least one subchannel in frequency domain, the time unit comprises at least one symbol, and the subchannel comprises at least one resource block; the first indication information comprises a quantity of the symbols occupied by a third resource in time domain and a quantity of resource blocks occupied by the third resource in frequency domain, the third resource comprises m control channel elements, m is an integer greater than or equal to 1, and the control channel element comprises at least one symbol in time domain and at least one resource block or subcarrier in frequency domain; sending, by the network device, first control information to the first communications device, wherein the first control information indicates a second resource, the second resource belongs to the first resource, and the second resource comprises the third resource and a fourth resource; the third resource is used by the first communications device to send the sidelink control information to a second communications device, the third resource comprises at least one symbol in time domain and at least one resource block in frequency domain; and the fourth resource is used by the first communications device to send the sidelink data to the second communications device based on the sidelink control information; wherein the first indication information further indicates at least one of the quantity m of the control channel elements comprised in the third resource, a quantity of symbols comprised in the control channel element in time domain, or a quantity of resource blocks or subcarriers comprised in the control channel element in frequency domain. Sending, by a network device, first indication information to a first communications device, wherein the first indication information indicates a first resource, the first resource is a resource set used to transmit sidelink information, and the sidelink information comprises sidelink control information and sidelink data; the first resource comprises at least one time unit in time domain and at least one subchannel in frequency domain, the time unit comprises at least one symbol, and the subchannel comprises at least one resource block; the first indication information comprises a quantity of the symbols occupied by a third resource in time domain and a quantity of resource blocks occupied by the third resource in frequency domain, the third resource comprises m control channel elements, m is an integer greater than or equal to 1, and the control channel element comprises at least one symbol in time domain and at least one resource block or subcarrier in frequency domain; sending, by the network device, first control information to the first communications device, wherein the first control information indicates a second resource, the second resource belongs to the first resource, and the second resource comprises the third resource and a fourth resource; the third resource is used by the first communications device to send the sidelink control information to a second communications device, the third resource comprises at least one symbol in time domain and at least one resource block in frequency domain; and the fourth resource is used by the first communications device to send the sidelink data to the second communications device based on the sidelink control information; wherein the first indication information further indicates at least one of the quantity m of the control channel elements comprised in the third resource, a quantity of symbols comprised in the control channel element in time domain, or a quantity of resource blocks or subcarriers comprised in the control channel element in frequency domain.