A control method for stabilizing excimer laser pulse energy, wherein an excimer laser is used to emit a plurality of pulse sequences, where each pulse sequence contains a plurality of pulses, and an energy level of each pulse is controlled by limiting a corresponding discharge voltage value of the pulse, where the discharge voltage value is calculated by a proportional-integral, PI, control algorithm, the control method comprising: obtaining a measured energy value of an n-th pulse in an m-th pulse sequence; calculating a difference between the measured energy value and a preset energy value; when n is a positive integer less than z, estimating the discharge voltage value of an (n+1)th pulse in the m-th pulse sequence according to a first mathematical model, wherein the z is an integer that lies in the range of 10 to 100; when n is an integer greater than (z-1), estimating the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence according to a second mathematical model; and generating the (n+1)th pulse in the m-th pulse sequence according to the discharge voltage value; where m is an integer greater than 1; wherein the first mathematical model is expressed in the following formula: HV m, n + 1 = PK p 1 E error m − 1, n + 1 + PK 1 PT 1 ∑ i = 1 m − 1 E error i, n + 1 where E error ( m - 1, n + 1)represents the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-1)th pulse sequence, ∑ i = 1 m − 1 E error i, n + 1 represents a sum of the difference between the measured energy value and the preset energy value of each (n+1)th pulse in the 1st to (m-1)th pulse sequences, P K p 1 is a proportional parameter of the PI control algorithm, P K 1 is an integral parameter of the PI control algorithm, and P T 1 is a control period parameter of the PI control algorithm; wherein an incremental form of the first mathematical model is expressed in the following formula: Δ HV m, n + 1 = PK p 1 E error m − 1, n + 1 − E error m − 2, n + 1 + PK p 1 PK 1 PT 1 E error m − 1, n + 1 where Δ HV ( m, n + 1) represents an amount of change between the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence and the (n+1)th pulse in the (m-1)th pulse sequence, E error ( m - 1, n + 1) is the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-1)th pulse sequence, E error ( m - 2, n + 1) is the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-2)th pulse sequence, P K p 1 is the proportional parameter of the PI control algorithm, P K 1 is the integral parameter of the PI control algorithm, and P T 1 is the control period parameter of the PI control algorithm; wherein the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence is expressed in the following formula: HV m, n + 1 = HV m − 1, n + 1 + Δ HV m, n + 1 where HV ( m - 1, n + 1) is the discharge voltage value of the (n+1)th pulse in the (m-1)th pulse sequence. obtaining a measured energy value of an n-th pulse in an m-th pulse sequence; calculating a difference between the measured energy value and a preset energy value; when n is a positive integer less than z, estimating the discharge voltage value of an (n+1)th pulse in the m-th pulse sequence according to a first mathematical model, wherein the z is an integer that lies in the range of 10 to 100; when n is an integer greater than (z-1), estimating the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence according to a second mathematical model; and generating the (n+1)th pulse in the m-th pulse sequence according to the discharge voltage value; where m is an integer greater than 1; wherein the first mathematical model is expressed in the following formula: HV m, n + 1 = PK p 1 E error m − 1, n + 1 + PK 1 PT 1 ∑ i = 1 m − 1 E error i, n + 1 where E error ( m - 1, n + 1)represents the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-1)th pulse sequence, ∑ i = 1 m − 1 E error i, n + 1 represents a sum of the difference between the measured energy value and the preset energy value of each (n+1)th pulse in the 1st to (m-1)th pulse sequences, P K p 1 is a proportional parameter of the PI control algorithm, P K 1 is an integral parameter of the PI control algorithm, and P T 1 is a control period parameter of the PI control algorithm; wherein an incremental form of the first mathematical model is expressed in the following formula: Δ HV m, n + 1 = PK p 1 E error m − 1, n + 1 − E error m − 2, n + 1 + PK p 1 PK 1 PT 1 E error m − 1, n + 1 where Δ HV ( m, n + 1) represents an amount of change between the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence and the (n+1)th pulse in the (m-1)th pulse sequence, E error ( m - 1, n + 1) is the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-1)th pulse sequence, E error ( m - 2, n + 1) is the difference between the measured energy value and the preset energy value of the (n+1)th pulse in the (m-2)th pulse sequence, P K p 1 is the proportional parameter of the PI control algorithm, P K 1 is the integral parameter of the PI control algorithm, and P T 1 is the control period parameter of the PI control algorithm; wherein the discharge voltage value of the (n+1)th pulse in the m-th pulse sequence is expressed in the following formula: HV m, n + 1 = HV m − 1, n + 1 + Δ HV m, n + 1 where HV ( m - 1, n + 1) is the discharge voltage value of the (n+1)th pulse in the (m-1)th pulse sequence.