In this paper, a simple and rapid sample pretreatment device integrating ultrasonication, centrifugation and ultrafiltration (UCU) was reported for preparation of trace analytes in complex matrices. The UCU device was composed of two parts, A and B. The sample and extraction solvent were put into Part B for ultrasonic extraction. Subsequently, Part A and Part B were integrated and sealed for centrifugation and ultrafiltration. Finally, the ultrafiltrate in Part A was taken out for subsequent detection. After optimization, the device was applied to rapid on-site screening of five illegally added chemical components in heat-clearing and detoxicating Chinese patent medicines by combining with electrospray ionization-ion mobility spectrometry (ESI-IMS). The method showed good performance in terms of linearity with correlation coefficients (R2) above 0.9976 and limits of detection (LODs) in the range of 0.049-0.391 μg mL-1. The recoveries were from 96.5 % to 100.8 %. The whole analysis process was within 11 min. The proposed method was further compared with other methods reported in the literature and the advantages and considerations were also explored. The results demonstrated that it was a simple, fast and accurate technique. The establishment of this method not only greatly improved the experimental efficiency but also avoided potential sample pollution brought by multiple sample transfer, and could provide a powerful means for rapid on-site analysis of trace analytes in complex matrices. Copyright © 2020 Elsevier B.V. All rights reserved.