Abstract: The present invention relates to a light selective absorbing coating and a production process thereof. The light selective absorbing coating consists of a composite material film deposited by reaction of iron chromium alloy and a non-metal gas with vacuum deposition technology. Said non-metal gas comprises gases of nitrogen and oxygen elements. The present invention also relates to a solar energy heat collecting element or solar energy selective absorbing coating system comprising said light selective absorbing coating and a production process thereof. The present invention further relates to use of said composite material film as a light selective absorbing coating of a solar energy heat collecting element or of a solar energy selective absorbing coating system.