The embodiment of the invention provides a determination method and system of an equipment threshold value. The method comprises the following steps: obtaining a data sample of the equipment, wherein the equipment is from the same totality; judging whether the data sample complies with normal distribution or not, and if the data sample complies with the normal distribution, determining an expectation and standard difference of the data sample; and according to the expectation and standard difference of the data sample, calculating a significant difference threshold value of the data sample, and taking the significant difference threshold value as the threshold value of the equipment. The threshold value, which is subjected to substantial change, of the equipment is effectively found out, the fault hidden dangers of various pieces of equipment can be removed in time, and the precision and the adaptability of the equipment threshold value can be improved.