A monitoring method, comprising: transmitting, by a terminal device, first information based on a first repetition number, wherein the first repetition number is less than or equal to a second repetition number, and the second repetition number is a maximum repeat transmission number of the first information; and starting or restarting, by the terminal device, a timer at an actual transmission end moment of the first information, and monitoring physical downlink control channel, PDCCH, search space before the timer expires or stops, characterized by, when the first repetition number is less than a second repetition number, timing duration of the timer is a sum of first duration and second duration, the first duration is preset duration or duration configured by a network device, the second duration is a difference between third duration and fourth duration, the third duration is duration required for transmitting the first information based on the first repetition number, and the fourth duration is duration required for transmitting the first information based on the second repetition number; wherein the monitoring, by the terminal device, physical downlink control channel PDCCH search space before the timer expires or stops comprises: before the timer expires or stops, skipping monitoring, by the terminal device, the PDCCH search space within fifth duration, and monitoring the PDCCH search space within sixth duration, wherein the timing duration of the timer is a sum of the fifth duration and the sixth duration, the fifth duration uses the actual transmission end moment as a start time, and the sixth duration uses a moment at which the timer expires or stops as an end time. transmitting, by a terminal device, first information based on a first repetition number, wherein the first repetition number is less than or equal to a second repetition number, and the second repetition number is a maximum repeat transmission number of the first information; and starting or restarting, by the terminal device, a timer at an actual transmission end moment of the first information, and monitoring physical downlink control channel, PDCCH, search space before the timer expires or stops, characterized by, when the first repetition number is less than a second repetition number, timing duration of the timer is a sum of first duration and second duration, the first duration is preset duration or duration configured by a network device, the second duration is a difference between third duration and fourth duration, the third duration is duration required for transmitting the first information based on the first repetition number, and the fourth duration is duration required for transmitting the first information based on the second repetition number; wherein the monitoring, by the terminal device, physical downlink control channel PDCCH search space before the timer expires or stops comprises: before the timer expires or stops, skipping monitoring, by the terminal device, the PDCCH search space within fifth duration, and monitoring the PDCCH search space within sixth duration, wherein the timing duration of the timer is a sum of the fifth duration and the sixth duration, the fifth duration uses the actual transmission end moment as a start time, and the sixth duration uses a moment at which the timer expires or stops as an end time.