Byusingthemethodofquantumstatistics,wedirectlyderivethepartitionfunctionofthebosonicandermionicfieldonblackplaneandobtaintheintegralexpressionoftheblackplane’sentropy,whichavoidsthedifficultyinsolvingthewaveequationofvariousparticles.Thenviatheimprovedbrick -wallmethod,membranemodel,wecalculatetheblackplane’sentropyandfindoutthatifwelettheintegralupperandlowerlimitsbothtendtothehorizon ,theentropyoftheblackplaneisproportionaltotheareaofhorizon.Inourresult,thestrippedtermandthedivergentlogarithmictermintheoriginalbrick -wallmethodnolongerexist.Inthewholeprocess,wedonottakeanyapproximation .Weofferanewsimpleanddirectwayofcalculatingtheentropyofdifferentcomplicatedblackholes.