Abstract: As an emerging clean energy resource, natural hydrogen requires reliable surface seepage detection, which directly affects the scientific validity of resource evaluation and exploration deployment. To address the inadequate representativeness of measured values, the poorly understood dynamic response characteristics, and the weak basis for quantitative calibration encountered with electrochemical handheld hydrogen detectors in natural hydrogen soil-gas surveys, a collaborative verification system based on electrochemical and chromatographic detection was established. Through reference gas experiments and field comparative sampling, the dynamic response process, stage-dependent bias characteristics, and sampling timing optimization strategy were systematically investigated. The results show that the response of the GA5000 can be divided into an initial rapid-response stage, a transitional stage, and a stable stage, with a clear concentration dependence. Under low-concentration conditions, more than 115 s was required to reach a stable state, and the deviation between the stabilized reading and the chromatographic value reached -68.8%. Under high-concentration conditions, the stabilization time was shortened to about 100 s, and the deviation decreased markedly to nearly zero. Field results further show that the direction of concentration change exerts a controlling influence on the discrepancy between the two instruments. During the rising stage, chromatographic values were generally higher than the synchronous handheld readings, with a maximum positive deviation of 58.9%. During the declining stage, chromatographic values were significantly lower than the handheld readings, with a maximum negative deviation of 218.2%. These results indicate that response lag dominates the bias during concentration increase, whereas memory effect becomes the main source of error during concentration decrease. Accordingly, a stage-specific sampling strategy is proposed: instantaneous sampling is preferred during the rising stage to reduce the influence of response delay on the identification of high-concentration values, whereas sampling during relatively stable intervals is recommended during the declining stage to mitigate overestimation caused by memory effect. On this basis, a collaborative calibration approach combining synchronous comparison with local correction was developed, establishing a technical chain from rapid field screening to accurate chromatographic quantification. The study provides technical support for the normalization and standardization of natural hydrogen surface detection methods.