The acquisition of weak magnetic signals is affected by factors such as environmental interference and unreasonable deployment of sensing equipment nodes, resulting in a large amount of interference noise in the collected signals. In order to improve the resolution of weak magnetic signal acquisition, an intelligent acquisition method for weak magnetic signals based on pyroelectric infrared sensors is proposed by combining array signal processing technology. Construct a node distribution array model for the intelligent acquisition of weak magnetic signals using pyroelectric infrared sensors, and combine phase shift correction and noise interference suppression methods to construct a filtering model for weak magnetic signal acquisition. The coherent array detection method based on signal waveform enhances the spatial features of weak magnetic signals, and combines multipath signal coherent matching technology and corresponding multiple DOA estimation techniques, Intelligent signal acquisition is achieved by enhancing and filtering the output signals of the array nodes of pyroelectric infrared sensors. The experimental results show that the output signal amplitude and phase gain of intelligent acquisition of weak magnetic signals using this method are good, with an output signal-to-noise ratio of up to 45.9 dB and a bit error rate of up to 0.55 bit for weak magnetic signals, indicating the practicality of this method.