A power determining method, applied to a terminal device, wherein the method comprises: obtaining M target ratios, wherein each of the target ratios is a ratio of one of M target power values to a maximum target power value, the maximum target power value is a maximum value of the M target power values, the M target power values are receive power values of M logical antenna ports, the M logical antenna ports are logical antenna ports of a target receive antenna of the terminal device, and M is an integer greater than 1; and determining a target receive power value based on the M target ratios, wherein the target receive power value is a receive power value of the target receive antenna, and the receive power value is an RSRP value or an RSSI value; wherein the determining a target receive power value based on the M target ratios comprises: in a case that all of the M target ratios are less than a preset threshold, determining (S202a) the target receive power value by using a first preset formula; or in a case that at least one of the M target ratios is greater than or equal to a preset threshold, determining (S202b) the target receive power value by using a second preset formula; characterized in that the first preset formula is: P = 10 * log 10 ∑ i = 1 M P i / M, wherein P is the target receive power value, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M; wherein the second preset formula is: P = ∑ i = 1 M F i P ratio 1,..., P ratio i,..., P ratio M * 10 * log 10 P i, wherein P is the target receive power value, P ratio ( i) is an i-th target ratio of the M target ratios, F i ( P ratio,..., P ratio ( i),...P ratio) is a conversion function, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M. obtaining M target ratios, wherein each of the target ratios is a ratio of one of M target power values to a maximum target power value, the maximum target power value is a maximum value of the M target power values, the M target power values are receive power values of M logical antenna ports, the M logical antenna ports are logical antenna ports of a target receive antenna of the terminal device, and M is an integer greater than 1; and determining a target receive power value based on the M target ratios, wherein the target receive power value is a receive power value of the target receive antenna, and the receive power value is an RSRP value or an RSSI value; wherein the determining a target receive power value based on the M target ratios comprises: in a case that all of the M target ratios are less than a preset threshold, determining (S202a) the target receive power value by using a first preset formula; or in a case that at least one of the M target ratios is greater than or equal to a preset threshold, determining (S202b) the target receive power value by using a second preset formula; characterized in that the first preset formula is: P = 10 * log 10 ∑ i = 1 M P i / M, wherein P is the target receive power value, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M; wherein the second preset formula is: P = ∑ i = 1 M F i P ratio 1,..., P ratio i,..., P ratio M * 10 * log 10 P i, wherein P is the target receive power value, P ratio ( i) is an i-th target ratio of the M target ratios, F i ( P ratio,..., P ratio ( i),...P ratio) is a conversion function, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M. in a case that all of the M target ratios are less than a preset threshold, determining (S202a) the target receive power value by using a first preset formula; or in a case that at least one of the M target ratios is greater than or equal to a preset threshold, determining (S202b) the target receive power value by using a second preset formula; characterized in that the first preset formula is: P = 10 * log 10 ∑ i = 1 M P i / M, wherein P is the target receive power value, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M; wherein the second preset formula is: P = ∑ i = 1 M F i P ratio 1,..., P ratio i,..., P ratio M * 10 * log 10 P i, wherein P is the target receive power value, P ratio ( i) is an i-th target ratio of the M target ratios, F i ( P ratio,..., P ratio ( i),...P ratio) is a conversion function, P ( i) is an i-th target power value of the M target power values, M is the number of logical antenna ports on the target receive antenna, and 1 ≤ i ≤ M.