A rapid calculation method for an 
electric power reliability index based on the multithread 
processing of cache data, which solves the problem of low analysis and calculation efficiency of an 
electric power reliability index. The method comprises: creating a 
data cache area in a memory, dividing same according to service data types, and using a 
management unit, a device registration date or power-
cut generation date as primary keys, so as to establish data blocks; establishing a change buffer area in each data block, recording a data change, and merging the change buffer area data with basic data at a 
definite time; and averagely allocating to a plurality of threads the data which is related to index calculation, so as to conduct basic index calculation, and then, merging the basic index calculation result of each thread, so as to calculate the comprehensive reliability index of each level of 
management unit. By means of the technical means of multi-data block caching service data, a data change buffer area and multithread 
processing, the basic 
data retrieval and calculation efficiency of an 
electric power reliability service are improved, thereby achieving the rapid calculation of an electric 
power reliability index.