It is of great significance to evaluate the breeding and utilization value of the major QTL of important traits in maize to promote the effective development of molecular design breeding and improve the efficiency of genetic improvement of germplasm resources. In our early study, a major QTL, qPEH6.02, for plant height was identified using the introgression line 1133B (tropical maize inbred line Tzi8 as the donor parent, temperate founder inbred line B73 as the recurrent parent). In present study, the near-isogenic introgression lines about qPEH6.02 were developed in the target segment by molecular marker tracking. The plant height and yield of near-isogenic introgression lines (1133BB73 and 1133BTzi8), and their hybrid crosses (crossed with both weakly heterosis inbred line of the same group and strong heterosis inbred line of the different group) were analyzed at 52500 plants/hm2, 67500 plants/hm2 and 82500 plants/hm2. The results showed that the plant height of 1133BTzi8 increased by 15.17-20.40 cm compared with its near-isogenic introgression line 1133BB73 under different planting densities, but only increased by 3.87-5.03 cm and 3.23-5.97 cm in its weak and strong hybrid crosses, respectively. At the same time, it was found that the plot yield of 1133BTzi8 was increased by more than 10% and the maximum yield was increased by 15.00% compared with that of 1133BB73 under different planting densities. The plot yield increased by more than 3% and the maximum yield increased by 8.85% in the hybrid crosses. The results indicate that the haplotype of qPEH6.02 from tropical maize inbred line Tzi8 has potential breeding utilization value in improving maize yield.