Existing wireless passive strain sensors suffer from limitations such as single-direction measurement, low sensitivity and large size, making them unsuitable for strain state evaluation of large metallic structures including aircraft wings, under complex loading conditions. To address these issues, a miniaturized wireless passive strain sensor array is proposed based on split ring resonator(SRR) with the advantages of high radiation capability, low loss, and high-quality factor and the principle of trigonometric functions and vector decomposition. The proposed sensor array consisting of three sensors arranged at 120° angles can reconstruct the magnitude and direction of strain field by extracting the resonant frequency shift. After the impedance parameters of the sensor are acquired by ADS software, the sensor structure miniaturization and impedance matching optimization design are carried out by HFSS software, aiming at the target of resonant frequency optimization. In addition, "force-magnetic" coupling analysis in COMSOL software verifies the performance of sensor's strain detection. Furthermore, the fabrication of the sensor is implemented based on the above analysis and optimization. Experimental results show that the sensitivity of proposed sensor in the electrical length and width directions is —1.517 KHz/με and —0.732KHz/με , respectively. The proposed sensor array achieves a strain magnitude detection accuracy within 8.5% and a direction detection error within 10° . The sensor array can achieve strain magnitude and direction detection on metallic surface with the ability of high sensitivity, compact size, and low cost.