A network device, comprising: a processing module, configured to obtain pieces of system information corresponding to N coverage grades within a coverage area of a cell, wherein a coverage grade G_i corresponds to a piece of system information S_i in the pieces of system information, where the system information S_i is different from a piece of system information S_j, wherein the system information S_j is a piece of system information corresponding to any coverage grade G_j in the N coverage grades other than the coverage grade G_i, 1≤j≤N, and i≠j, wherein a larger i indicates poorer receiving performance for a user equipment belonging to the coverage grade G_i; and a sending module, configured to send the pieces of system information over a target channel by using different sending parameters, wherein a sending parameter used to send the system information S_i is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when user equipment belonging to the coverage grade G_i is enabled to reliably receive the system information S_i over the target channel; wherein i and N are positive integers, and 1≤i≤N; characterized in that: the system information S_i comprises a diff_i and a comm, wherein: the diff_i is a piece of partial system information obtained by the processing module for the coverage grade G_i; and the comm is a piece of common-content partial system information for the system information S_i and the system information S_j; wherein the comm is sent over the target channel by using a first sending parameter, wherein the first sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when user equipment belonging to a coverage grade G_N is enabled to reliably receive the comm over the target channel; the diff_i is sent over the target channel by using a second sending parameter, wherein the second sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when the user equipment belonging to the coverage grade G_i is enabled to reliably receive the diff_i over the target channel. a processing module, configured to obtain pieces of system information corresponding to N coverage grades within a coverage area of a cell, wherein a coverage grade G_i corresponds to a piece of system information S_i in the pieces of system information, where the system information S_i is different from a piece of system information S_j, wherein the system information S_j is a piece of system information corresponding to any coverage grade G_j in the N coverage grades other than the coverage grade G_i, 1≤j≤N, and i≠j, wherein a larger i indicates poorer receiving performance for a user equipment belonging to the coverage grade G_i; and a sending module, configured to send the pieces of system information over a target channel by using different sending parameters, wherein a sending parameter used to send the system information S_i is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when user equipment belonging to the coverage grade G_i is enabled to reliably receive the system information S_i over the target channel; wherein i and N are positive integers, and 1≤i≤N; characterized in that: the system information S_i comprises a diff_i and a comm, wherein: the diff_i is a piece of partial system information obtained by the processing module for the coverage grade G_i; and the comm is a piece of common-content partial system information for the system information S_i and the system information S_j; wherein the comm is sent over the target channel by using a first sending parameter, wherein the first sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when user equipment belonging to a coverage grade G_N is enabled to reliably receive the comm over the target channel; the diff_i is sent over the target channel by using a second sending parameter, wherein the second sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when the user equipment belonging to the coverage grade G_i is enabled to reliably receive the diff_i over the target channel. the diff_i is a piece of partial system information obtained by the processing module for the coverage grade G_i; and the comm is a piece of common-content partial system information for the system information S_i and the system information S_j; wherein the comm is sent over the target channel by using a first sending parameter, wherein the first sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when user equipment belonging to a coverage grade G_N is enabled to reliably receive the comm over the target channel; the diff_i is sent over the target channel by using a second sending parameter, wherein the second sending parameter is a physical-layer parameter and/or a higher-layer parameter that are/is used by the sending module when the user equipment belonging to the coverage grade G_i is enabled to reliably receive the diff_i over the target channel.