A time allocation method, comprising: allocating, by a management device, a first sharing duration to a first group, and allocating a second sharing duration to a second group, wherein the first group comprises at least one node device managed by the management device, and the second group comprises at least one node device managed by the management device, the first sharing duration is used by the at least one node device comprised in the first group to send a service packet, and the second sharing duration is used by the at least one node device comprised in the second group to send a service packet; allocating, by the management device, a contention duration to a node device managed by the management device, wherein the contention duration is used by the node device managed by the management device to send a service packet by contending for a channel; and sending (203, 405), by the management device, at least one first notification message, wherein the at least one first notification message is used to notify that the at least one node device comprised in the first group corresponds to the first sharing duration and the at least one node device comprised in the second group corresponds to the second sharing duration, and is used to determine the contention duration by the at least one node device comprised in the first group and the at least one node device comprised in the second group; wherein before the allocating, by the management device, the first sharing duration to the first group, and allocating the second sharing duration to the second group, the method further comprises: determining, by the management device, a quantity of groups, wherein the quantity of groups is a quantity of groups obtained after the management device groups the node device managed by the management device; and determining, by the management device, a node device corresponding to each group in the obtained groups; and the determining, by the management device, a quantity of groups comprises: determining, by the management device, the quantity of groups based on preset required latency duration and transmission duration of the service packet. allocating, by a management device, a first sharing duration to a first group, and allocating a second sharing duration to a second group, wherein the first group comprises at least one node device managed by the management device, and the second group comprises at least one node device managed by the management device, the first sharing duration is used by the at least one node device comprised in the first group to send a service packet, and the second sharing duration is used by the at least one node device comprised in the second group to send a service packet; allocating, by the management device, a contention duration to a node device managed by the management device, wherein the contention duration is used by the node device managed by the management device to send a service packet by contending for a channel; and sending (203, 405), by the management device, at least one first notification message, wherein the at least one first notification message is used to notify that the at least one node device comprised in the first group corresponds to the first sharing duration and the at least one node device comprised in the second group corresponds to the second sharing duration, and is used to determine the contention duration by the at least one node device comprised in the first group and the at least one node device comprised in the second group; wherein before the allocating, by the management device, the first sharing duration to the first group, and allocating the second sharing duration to the second group, the method further comprises: determining, by the management device, a quantity of groups, wherein the quantity of groups is a quantity of groups obtained after the management device groups the node device managed by the management device; and determining, by the management device, a node device corresponding to each group in the obtained groups; and determining, by the management device, a quantity of groups, wherein the quantity of groups is a quantity of groups obtained after the management device groups the node device managed by the management device; and determining, by the management device, a node device corresponding to each group in the obtained groups; and the determining, by the management device, a quantity of groups comprises: determining, by the management device, the quantity of groups based on preset required latency duration and transmission duration of the service packet.