In order to determine the pest control potential of Harmonia axyridis against Tuberculatus castanocallis, the predation function, seeking effect and disturbance response of H. axyridis against T. castanocallis were studied in laboratory. The results showed that the H. axyridis's predation function responses to T. castanocallis were all consistent with the Holling-Ⅱ model. The maximum daily theoretical predation of H. axyridis on T. castanocallis in descending order was as follows: 4^th instar (447.97 individuals), female adult (387.53 individuals), male adult (379.73 individuals), 3^rd instar (243.45 individuals), 2^nd instar (122.75 individuals), and 1^st instar (62.62 individuals). The seeking effect of H. axyridis decreased with the increase of the density of T. castanocallis. With the increase of its own density, the single-head predation amount and predation ratio of H. axyridis gradually decreased, and the competition intensity of allocation gradually increased, which was consistent with the Hassell interference model. The densities of H. axyridis of different insect states had obvious interference effects on the predation of T. castanocallis, and the coefficient of interference in descending order as follows: the 4^th instar larvae (0.7257), female adult (0.6907), male adult (0.6703), 3^rd instar (0.6387), 2^nd instar (0.3425), 1^st instar (0.3392). The results showed that H. axyridis had a good potential to control T. castanocallis, and provided a theoretical basis for the efficient use of H. axyridis to control T. castanocallis.