Using the vector potential, the expression for calculating inductance of air-cored solenoid coil is derived in the dissertation . and the calculating methods of function t in the calculating expression are given for the convenience of the calculation of inductance while the precision is not strictly requested 利用矢量磁位a直接推導(dǎo)出了通電空心圓柱線圈電感的計(jì)算表達(dá)式,給出了求解計(jì)算式中函數(shù)t的計(jì)算方法,以方便精度要求不高時(shí)的電感計(jì)算。