A light dimming method for alleviating inter-frame flicker, comprising: calculating an average luminance value Avg data when a sender sends data frames in a physical layer; judging whether inter-frame flicker is generated when the sender sends data or not according to a ratio of Avg data to an average luminance value Avg light in an illumination state; and if the inter-frame flicker is generated when the sender sends the data, inserting, by the sender, a dimming frame in an idle pattern, wherein the dimming frame is used for compensating for a luminance difference between Avg data and Avg light; wherein judging whether the inter-frame flicker is generated when the sender sends the data or not according to the ratio of Avg data to Avg light comprises: judging whether the following formula is true or not according to Avg data and Avg light: Avg data − Avg light Avg light ≤ K, where K is a constant; and when the formula is not true, determining that the inter-frame flicker is generated when the sender sends the data; wherein inserting, by the sender, the dimming frame in the idle pattern comprises: calculating, according to the following formula, a duty cycle range of a dimming frame, α, to be inserted: 1 − K × A ≤ α ≤ K + 1 × A, where A represents a duty cycle of a line coding method adopted for a physical layer, and K is a constant; and inserting and sending, by the sender, a dimming frame adopting any duty cycle within the calculated duty cycle range in the idle pattern. calculating an average luminance value Avg data when a sender sends data frames in a physical layer; judging whether inter-frame flicker is generated when the sender sends data or not according to a ratio of Avg data to an average luminance value Avg light in an illumination state; and if the inter-frame flicker is generated when the sender sends the data, inserting, by the sender, a dimming frame in an idle pattern, wherein the dimming frame is used for compensating for a luminance difference between Avg data and Avg light; wherein judging whether the inter-frame flicker is generated when the sender sends the data or not according to the ratio of Avg data to Avg light comprises: judging whether the following formula is true or not according to Avg data and Avg light: Avg data − Avg light Avg light ≤ K, where K is a constant; and when the formula is not true, determining that the inter-frame flicker is generated when the sender sends the data; wherein inserting, by the sender, the dimming frame in the idle pattern comprises: calculating, according to the following formula, a duty cycle range of a dimming frame, α, to be inserted: 1 − K × A ≤ α ≤ K + 1 × A, where A represents a duty cycle of a line coding method adopted for a physical layer, and K is a constant; and inserting and sending, by the sender, a dimming frame adopting any duty cycle within the calculated duty cycle range in the idle pattern. judging whether the following formula is true or not according to Avg data and Avg light: Avg data − Avg light Avg light ≤ K, where K is a constant; and when the formula is not true, determining that the inter-frame flicker is generated when the sender sends the data; where K is a constant; and when the formula is not true, determining that the inter-frame flicker is generated when the sender sends the data; wherein inserting, by the sender, the dimming frame in the idle pattern comprises: calculating, according to the following formula, a duty cycle range of a dimming frame, α, to be inserted: 1 − K × A ≤ α ≤ K + 1 × A, where A represents a duty cycle of a line coding method adopted for a physical layer, and K is a constant; and inserting and sending, by the sender, a dimming frame adopting any duty cycle within the calculated duty cycle range in the idle pattern. where A represents a duty cycle of a line coding method adopted for a physical layer, and K is a constant; and inserting and sending, by the sender, a dimming frame adopting any duty cycle within the calculated duty cycle range in the idle pattern.