The invention discloses a self-
adaptive method and device for eliminating interference of multiple antennae through diversity and mergence. The method comprises the following steps of: measuring 
noise power of each receiving antenna; judging whether the ratio of the sum of 
diagonal elements of an NI (
Noise Index) matrix of a data carrier to be detected to an average value of the 
noise power of all receiving antennae is larger than a preset threshold value; if so, carrying out interference suppression and mergence detection on the data carrier to be detected; and if not, carrying out noninterference suppression and mergence detection on the data carrier to be detected. Starting from an NI 
estimation matrix as the most fundamental factor influencing an IRC (Interference Rejection Combining) merging 
algorithm, whether the currently obtained NI matrix contains more interference components is judged through the specific numerical value characteristic of the NI matrix, and then, an IRC 
algorithm or MRC (
Mixed Radix Conversion) 
algorithm is selected, so that the 
system obtains the optimal performance.