We propose a scheme for a state-insensitive optical dipole trap for single cesium atoms using a silica microcapillary tube tip. The end of microcapillary tube tip is flat. Simulations show that the trapping light beam output from microcapillary tube tip interferes and can form a subwavelength-trap with a full width at half-maximum of 0.67 μm. The trap is small enough to trap single atoms. The trap depth is more than 1 mK when the optical power of the trapping light guided by the microcapillary tube tip is only a few milliwatts. The effects of two imperfections, roughness of end surface and cutting angle, are estimated. The trapping depth for single atom trapping can be more than 1 mK when the average rms amplitude and average correlation length of tip surface roughness is smaller than 0.15 μm and the cutting angle is smaller than 16 degrees. Tip sizes on the order of microns are small enough to be combined within micro/nano structures for hybrid systems.