Abstract: An improved extended tanh-function method, which combines fractional transform and extended tanh-function method, is abtained to find exact solutions of nonlinear space-time fractional differential equations. With the aid of computation software mathematical, space-time fractional coupled Berger equations are solved, some new exact solutions are gained by the method.

Key words: complex-transform-Tanh-function method, modified Riemann-Liouville derivative, space-time fractional coupled Burger equations

摘要： 将分数阶复变换方法和tanh函数方法相结合，得到了一种用来求解时-空分数阶非线性微分方程精确解的复变换-tanh函数方法。借助于软件Mathematica的符号计算功能，使用该方法求解了分数阶对偶Burger方程，得到了分数阶对偶Burger方程的新的精确解。

关键词: 复变换-tanh函数方法, 修正Riemann-Liouville导数, 时空分数阶对偶Burger方程