Firstly , the voronovskaja type formula of asymptotic expansion of this kind of operators is given . then the approximation of the bounded variation functions by the kinds of operators is discussed 第一節(jié)給出該算子的voronovskaja型漸近展開公式;第二節(jié)討論該算子對(duì)有界變差函數(shù)的逼近。