This paper finds out the mean value and variance of load sequence in a period of time based on statistics and then works out the bias ratio of every point in load sequence using corresponding calculation formula and at the same time compares it with threshold value so that " unhealthy data " can be removed and accurate and effective load forecasting can be ensured 本文利用统计学的方法，求出某段时间内负荷序列中的均值与方差，再利用偏离率的计算公式计算出负荷序列中每一点的偏离率，并与阈值相比较，从而除去“不良数据” ，为准确有效地进行负荷预测提供了保证。
