The invention discloses an upper guide bearing bush temperature detection method for a power plant generator set, and is applied to a power plant control system. The generator set comprises a guide bearing, wherein the guide bearing comprises an upper guide bearing bush. The detection method comprises the following steps that: obtaining the revolving speed information of the generator set; judgingwhether the revolving speed information is greater than zero or not, and if the revolving speed information is greater than zero, obtaining the temperature information of the upper guide bearing bush; obtaining a preset temperature threshold value; judging whether the temperature information is greater than the preset temperature threshold value or not; and if the temperature information is greater than the preset temperature threshold value, determining that the temperature of the upper guide bearing bush is overhigh, and generating a corresponding detection result. A traditional remote monitoring system is improved, a three-dimensional model of the upper guide bearing bush is established on the basis of the traditional remote monitoring system, parameter information or structure information related to the upper guide bearing bush is monitored in real time, so that the fault of the upper guide bearing bush is remotely accurately detected, and detection accuracy and detection efficiency are improved.