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Many animals and insects (e.g. geckos, beetles, etc.) in nature use fine hairs on their foot for generation of robust adhesion, which has inspired many researchers to fabricate fibrillar structures and study their adhesion. However, it has been experimentally found that the bioinspired fibrillar structures cannot always improve the interfacial adhesion compared with the smooth surfaces without micro-structures. Therefore, how to achieve the robust adhesion of fibrillar adhesives is an open question until now. In the present paper, a theoretical model of a micro-pillar arrayed surface in contact with a rigid substrate is established to investigate the interfacial adhesion mechanism considering the effects of the geometrical parameters and material properties of the micro-pillar arrayed surfaces. It is found that the adhesion of the micro-pillar arrayed surface depends not only on the adhesion force of a single micro-pillar, but also on the efficiency of load sharing among the micro-pillars. The efficiency of load sharing dominated by the interaction between the micro-pillars and micro-pillar and the backing layer is revealed, from which it is indicated that the efficiency of loading sharing among the micro-pillars increases with increasing the aspect ratio of the micro-pillar, the ratio between the Young’s modulus of micro-pillar and backing layer and the micro-pillar separation, but decreases with the increase of radius of the micro-pillar arrayed surface. Such the results can lead to obtaining the condition of equal load sharing among. Finally, adhesion maps of the micro-pillar arrayed surface are obtained, from which the conditions of micro-pillar arrays increasing or decreasing the interfacial adhesion are clearly demonstrated. The obtained results in the present paper can not only deepen the understanding of the adhesion mechanism of micro-pillar arrayed adhesives, but also provide theoretical design principles to achieve the robust adhesion of fibrillar adhesives.