Flowering time is an important agronomic trait that determines ecological adaptation, maturity progression, and regional utilization value in maize. Systematic evaluation of flowering time variation in maize inbred lines and identification of stable association loci across multiple environments can provide useful references for the screening of early-maturing germplasm and molecular breeding. To dissect the genetic basis of flowering time traits and identify key loci controlling these traits, 352 maize inbred lines with diverse genetic backgrounds were used in this study. Field trials were conducted in Changping, Beijing in 2024, Yuci, Shanxi in 2024, and Shunyi, Beijing in 2025. Three flowering time traits, namely days to tasseling (DT), days to pollen shedding (DP), and days to silking (DS), were accurately evaluated. Based on 11,004,183 high-quality single nucleotide polymorphism (SNP) markers obtained from whole-genome resequencing, genome-wide association studies (GWAS) were performed using the FarmCPU model. The results showed that the three flowering time traits exhibited abundant phenotypic variation, with broad-sense heritability ranging from 0.93 to 0.94. Highly significant positive correlations were observed among the three traits. A total of 113 SNPs significantly associated with the three traits were detected by GWAS. Among them, six non-redundant major-effect loci were stably detected across multiple environments, and two loci showed co-localization patterns. Further analysis of 12 candidate genes within the intervals of these two stable loci identified three significantly associated candidate genes: Zm00001d027419, encoding a bHLH transcription factor; Zm00001d050151, encoding sucrose synthase; and Zm00001d050153, encoding a reticulon-like protein. Haplotype analysis showed that the favorable haplotypes of these three genes were significantly associated with early flowering. These findings provide new insights into the molecular regulatory mechanism of flowering time in maize and offer valuable genetic resources and theoretical support for marker-assisted selection and genomic breeding of early-maturing maize.