Abstract: In order to investigate the sensitivity of Digitaria sanguinalis to commonly used pre-emergence and post-emergence herbicides in dry direct-seeding rice fields in Anhui Province of China and explore their resistance mechanism, the whole-plant bioassay was employed to determine the sensitivity level of 15 populations of D. sanguinalis to five post-emergence and five pre-emergence herbicides, collected from dry direct-seeding rice fields in Anhui Province. Meanwhile, the target genes of resistant populations were detected and synergistic adjuvants for post-emergence herbicides were screened. The results showed that among post-emergence herbicides, cyhalofop-butyl and metamifop exhibited significant inhibitory effects on 80% of the D. sanguinalis populations. However, three populations (M1, M6, M11) showed clear resistance to both herbicides, with resistance indices of 17.85-, 7.63-, 6.99 for cyhalofop-butyl and 19.23-, 4.85-, 9.04 for metamifop, respectively. The inhibitory effects of three post-emergence herbicides (penoxsulam, bispyribac-sodium, quinclorac) on D. sanguinalis were relatively poor. Among the pre-emergence herbicides tested, all 15 populations showed relatively high sensitivity to four of the five herbicides, except pendimethalin. The order of sensitivity from highest to lowest was as follows: acetochlor = oxadiargyl > clomazone > pretilachlor. Target gene detection revealed that no target site mutations were identified in M1, M6, and M11 populations, which have developed moderate or high levels of resistance to cyhalofop-butyl and metamifop, indicating the presence of alternative resistance mechanisms. The screening tests of synergistic additives indicated that the mixture of cyhalofop-butyl with high-molecular-weight polymers enhances the control efficacy against the indoor potted high-resistant population (M1). The study aimed to provide guidance for efficient control of D. sanguinalis in dry direct-seeding rice fields.