The　Black-Scholes　model　(B-S　model)　is　a　common　used　option　pricing　model,　which　assumes　that　the　volatility　and　the　interest　rate　are　constants.　However,　the　empirical　analysis　shows　that　the　option　prices　obtained　from　the　B-S　model　are　quite　different　from　the　market　prices.　The　traditional　improve-ment　to　the　B-S　model　is　to　replace　the　volatility　constants　or　interest　rate　constants　with　variables.　This　paper　proposes　the　concept　of　modification　term　of　Black-Scholes　model,　which　is　different　from　the　traditional　methods.　The　errors　of　the　B-S　model　may　be　calculated　through　the　market　data,　and　is　fitted　as　a　function　of　a　functional　implied　volatility　and　the　option　gamma.　The　fitted　function　can　be　considered　as　the　modification　term　of　the　Black-Scholes　model.　The　functional　implied　volatility　can　be　constructed　by　using　the　Gaussian　semi-parametric　implied　volatility　model　proposed　by　Ref.　[4].　Experimental　results　show　that　the　modified　model　has　a　better　predictive　effect　on　option　pricing.　©　2021　IEEE.