As to the estimating process of GARCH (1, 1) model, the author adopted Maximum Likelihood Estimation and BHHH algorithm to get unknown parameters' value.

至于GARCH(1,1)模型的估计过程，本文用最大似然估计法和BHHH算法求未知参数值。

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But the methods of estimation of parameter of the GARCH models, BHHH and GMM, may become invalid because they usually meet the situation that the middle data fluctuate greatly.

而GARCH模型参数估计的主要方法BHHH算法和广义矩方法在实际运算中常遇到中间数据震荡从而导致算法整体失效等。

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