中文摘要：

用 infinitesimals 的古典谎言方法，我们首先获得对称(2+1 ) 维的 Burgers-Korteweg-de-Vries (3D-BKdV ) 方程。然后，我们用对称减少 the3D-BKdV 方程并且给一些 3D-BKdV 方程的准确答案。Whenusing 直接方法，我们限制一个条件并且得到在新答案和旧的之间的一种关系。给 3D-BKdV 方程的一个答案，我们能从关系得到新的。在使用古典谎言方法和由使用直接方法获得了那获得的对称之间的关系也被提及。最后，我们给 3D-BKdV 方程的能量守恒定律。

英文摘要：

Using the classical Lie method of infinitesimals, we first obtain the symmetry of the （2＋1）-dimensional Burgers-Korteweg-de-Vries （3D-BKdV） equation. Then we reduce the 3D-BKdV equation using the symmetry and give some exact solutions of the 3D-BKdV equation. When using the direct method, we restrict a condition and get a relationship between the new solutions and the old ones. Given a solution of the 3D-BKdV equation, we can get a new one from the relationship. The relationship between the symmetry obtained by using the classical Lie method and that obtained by using the direct method is also mentioned. At last, we give the conservation laws of the 3D-BKdV equation.