In view of the gripping and conveying device which belongs to the existing vertical corn harvest header with low gripping uniformity, stability and high failure rate, a clearance located gripping and conveying device with simple structure, favorable conveying effect and high reliability was developed. The device solved the stem gesture adjusting, breaking stem and blocking problems in the working process of vertical corn reaper;ensured that the stem would be located, stably conveyed and directionally fed;and improved the reliability of vertical roller corn harvest header. A corn clearance located and conveyed method was proposed and the designation method of the main structure and motion parameter of clearance located gripping and conveying device was analyzed, its main structure and working parameters that influenced the reliability of ordered located conveying were explored and then the relevant design theory was established. A theory reference was provided for design of vertical roller gripping and conveying device. The main parameter influenced the gripping and conveying quality was determined by orthogonal test method which included the clearance of the gripping and conveying track, the velocity of the clearance gripping and conveying chain and the length of the clearance gripping and conveying chain, and the optimal result showed that the best combination was A2B3C3 group that the length of the clearance gripping and conveying chain was 130cm, the clearance of track was 3.1cm, the velocity of the clearance gripping and conveying chain was 4.5m/s. And the corresponding performance indexes were as follows: the success ratio of stem gesture feeding was 92.5%, the ration of break stem was 0.25%, the conveying process was stable and without blocking, which could completely satisfy the requirement of the vertical roller corn reaper. This research can supply the study basis to structure improvement and performance optimizaiton of delivery mechanism for vertical-rollers type of corn harvester.