The invention relates to an accumulative sampling device using a composite characteristic adsorbent as a receiving phase and used for monitoring the concentration of polar organic pollutants in water. The accumulative sampling device is based on a synthetic high molecular membrane material and a mixed-mode solid phase extraction adsorbent, the composite adsorbent is placed between two layers of high molecular membranes to form a sampler adopting a sandwich structure, and the accumulative sampling device can enrich a variety of the polar organic pollutants in water at the same time. In allusion to differences among the polar organic pollutants in water, the accumulative sampling device uses five characteristic solid phase extraction adsorbents to form the mixed-mode adsorbent, and has a polarity range-widened reverse phase adsorption effect, a weak anion exchange effect and a weak cation exchange effect at the same time, and has a broad-spectrum adsorption effect on the polar organic pollutants in water; meanwhile, the accumulative sampling device uses a high molecular osmotic membrane with a specific pore size range as an outer membrane, so that free passing of water, compounds in a freely dissolved state and compounds in a colloidal state can be ensured, the adsorption equilibrium time is shortened, and thus the accumulative sampling device can be used as a balanced sampler for monitoring the organic trace pollutants in water and performing biological simulative sampling.