Abstract: Based on supercontinuum injection, a new method of high-energy femtosecond parametric amplification is put forward. The method overcomes the gain narrowing effect of the conventional 1 053 nm low-energy amplification and realizes the synchronization between 800 nm and 1 053 nm laser pulses. Through systematic experimental investigation, a broadband 1 053 nm laser pulse is obtained, with energy exceeding 4 mJ,which is the maximum energy obtained directly through a femtosecond OPA in the world.