【Objective】To explore the effects of different application methods of compound bacterial agents on the growth, root morphology and photosynthetic characteristics of Chinese cabbage seedlings, so as to provide theoretical basis for the relieving effect of compound bacterial agents on the continuous cropping obstacle of Chinese cabbage. 【Methods】Three kinds of compound fungi application methods, T1 (foliar spraying), T2 (soil application) and T3 (foliar spraying + soil application), were set up with CK (no compound fungi application) as control.【Results】Compared with CK, T1 treatment significantly increased plant height, stem diameter and root length by 91.81%, net photosynthetic rate by 24.55%, Fv/Fm and ΦPSII by 5.70% and 23.93%, respectively. Correlation showed that each index had a strong relationship. By principal component analysis, 23 single indexes were converted into 3 independent comprehensive indexes, and the cumulative contribution rate could reach 85.399%. The comprehensive weight values of ΦPSII, qp, fresh weight of underground part, Fv/Fm, number of root connections, and plant height were relatively high. Conclusion: Foliar spraying compound bacterial agent is the best way to promote seedling growth, improve root configuration and enhance photosynthesis in continuous cropping of Chinese cabbage, and it is the best way to apply compound bacterial agent.