Mechanized transplanting is an important operation of rice production. Studying quantitative variation of transplanter technical parameter with pond parameters can not only improve transplanter operation efficiency, but also provide theoretical basis for determining suitable pond parameters for different transplanters and selecting appropriate transplanter for different pond scales. Based on transplanters operating mechanism and surveying results, transplanter operating modes and paths of transplanters were clarified. Mathematical model for transplanter time utilization rates varied with pond parameters under two seedling adding modes were established according to calculation models for pure operation time, seedling and fertilizer adding time, turning time, and other time parameters. The method of multi-point synchronous tracking measurement was adopted to obtain various time items of five typical transplanters. Based on the established models and tested time items, data sets of time utilization rates of five transplanters operating under two operation modes were calculated by using Matlab 2020a program, and then time utilization rate variations were analyzed with different scopes of pond length and area. Coupling relationships between pond length and area suitable for each transplanter at three different time utilization rates were determined as further conclusions. The results showed that seeding adding times was the key reason why transplanter time utilization rate fluctuantly changed with pond length and area. Pond length and area suitable for transplanters coupling varied inversely when time utilization rate equaled to 0.45 and 0.5, and distributed significantly in multiple regions and multi-segmented lengths when time utilization rate equaled to 0.55. The eigenvalues of pond parameters suitable for each transplanter at different time utilization rates were determined. The research results improved the theory of agricultural machinery units and provided theoretical and technical support for selecting suitable transplanter based on different pond parameters.