通常情况下,期权定价研究都假定股票价格的波动率和期望收益率为常数.假定波动率和期望收益率为股票价格的一般函数.利用体积有限元方法研究了美式期权定价模型下的Black-Scholes偏微分方程,获得了美式期权所满足的较高精度的隐式差分格式,最后,给出了该方法的误差估计. Generally speaking, the option pricing research assumes that the stock price volatility and the expected return rate are constant, assuming the volatility and the expected return rate as the general function of the stock price.The volume finite element method is used to study the Black- Scholes partial differential equation, the higher accuracy implicit difference scheme satisfied by the American option is obtained. Finally, the error estimation of this method is given.