This study investigated the effects of different inducer treatments on the stress-resistant physiological indexes, agronomic traits, and yield of flax leaves, aiming to provide a theoretical basis and application references for the cultivation, quality improvement, and yield increase of flax. Using flax cultivar ‘Neiya 14’ as the test material, measurements and comparisons were carried out on the plant height, technical length, number of branches, yield components, and leaf physiological indicators of flax treated with different resistance inducers, including Aitaling, chitosan oligosaccharide, and plant immune proteins. The results indicated significant differences in the effects of different resistance inducers. Compared with other treatments, plant immune protein and Atailing treatments significantly enhanced flax stress resistance: the soluble sugar contents were 123.71 and 122.73 mg/g, proline contents were 64.08 and 62.62 μg/g, and SOD activities were 129.87 and 123.91 U/g, respectively, both significantly higher than the clear water control treatments. Aitaling, plant immune protein, and ‘Jiaojiang No.1’ promoted the growth and development of flax. Specifically, the treatment with ‘Jiaojiang No.1’ resulted in the highest plant height, reaching 63.77 cm; while the treatment with Aitaling achieved the longest berry length of 43.70 cm and the highest number of effective berries per plant at 28.83. The treatments with plant immune protein and Aitaling achieved the highest equivalent output, reaching 2530.13 and 2538.17 kg/hm², respectively representing significant increases of 6.03% and 6.33% compared to the clear water control treatment. The treatments with Aitaling, plant immune protein, and ‘Jiaojiang No.1’ exhibited significant effects in promoting flax growth, increasing yield, and enhancing stress resistance, thus showing considerable application potential in flax cultivation.