A free-wheeling diode control method, comprising: obtaining (S201, S301) a first pulse width value of a transistor used as a free-wheeling diode (Q2, Q4) in a power switching apparatus; obtaining (S201, S301) a second pulse width value of the transistor used as the free-wheeling diode (Q2, Q4); characterised by obtaining the first pulse width value according to Toff 1 = 2 Lv Vo IL or Toff 1 = 2 Lv Vo − Vin IL, where Toff1 denotes the first pulse width value, Lv denotes an inductance value of an inductor in the power switching apparatus, IL denotes a current of the inductor, Vo denotes an output voltage of the power switching apparatus, and Vin denotes an input voltage of the power switching apparatus; obtaining the second pulse width value according to Toff 2 = Vin − Vo Vo Ton or Toff 2 = Vin Vo − Vin Ton, where Toff2 denotes the second pulse width value, and Ton denotes a third pulse width value of a main control transistor (Q1, Q3) in the power switching apparatus; determining (S202, S302) whether a sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus meets a first preset condition, wherein the first preset condition includes: less than or equal to a first preset pulse width value; obtaining a determining result, wherein the determining result includes: the sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus meets the first preset condition, or the sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus does not meet the first preset condition; and determining, according to the determining result, to control conduction of the transistor used as the free-wheeling diode (Q2, Q4) according to the first pulse width value or the second pulse width value. obtaining (S201, S301) a first pulse width value of a transistor used as a free-wheeling diode (Q2, Q4) in a power switching apparatus; obtaining (S201, S301) a second pulse width value of the transistor used as the free-wheeling diode (Q2, Q4); characterised by obtaining the first pulse width value according to Toff 1 = 2 Lv Vo IL or Toff 1 = 2 Lv Vo − Vin IL, where Toff1 denotes the first pulse width value, Lv denotes an inductance value of an inductor in the power switching apparatus, IL denotes a current of the inductor, Vo denotes an output voltage of the power switching apparatus, and Vin denotes an input voltage of the power switching apparatus; obtaining the second pulse width value according to Toff 2 = Vin − Vo Vo Ton or Toff 2 = Vin Vo − Vin Ton, where Toff2 denotes the second pulse width value, and Ton denotes a third pulse width value of a main control transistor (Q1, Q3) in the power switching apparatus; determining (S202, S302) whether a sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus meets a first preset condition, wherein the first preset condition includes: less than or equal to a first preset pulse width value; obtaining a determining result, wherein the determining result includes: the sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus meets the first preset condition, or the sum of the first pulse width value and the third pulse width value of the main control transistor (Q1, Q3) in the power switching apparatus does not meet the first preset condition; and determining, according to the determining result, to control conduction of the transistor used as the free-wheeling diode (Q2, Q4) according to the first pulse width value or the second pulse width value.