We demonstrate a new four-core fiber optic tweezers by polishing the end face of a four-core fiber into a truncated pyramid that is asymmetric to fiber cores. Optical intensity propagation and distribution are modeled numerically, and rotation function is developed by means of calculating three-dimensional trapping force and torque in ray optics regime. Simulation results show our tweezers is a feasible approach that can trap and rotate microscopic spheroid objects stably.