Dispersion ultimately limits the efficiency of the nonlinear process in the optical waveguide. Traditional dispersion engineering method is to tailor the cross-section of the waveguide with both of the height and width. However, the fabrication process limits the design freedom of the height in some cases. To solve the problem, we develop a dispersion engineering technique based on spatial mode coupling. Just by tailoring the width of waveguide without altering the height, the proposed method achieves anomalous dispersion with a range of 70 nm numerically and experimentally changes the dispersion of a micro-ring resonator from -750 ± 30 ps/nm/km to 1300 ± 200 ps/nm/km over a wavelength range of 25 nm with high Q of 0.8 million on the Si3N4/SiO2 waveguide platform. This technique overcomes the restrict from the fabrication process to the optical waveguide on the dispersion control and can enlarge application of the nonlinear optics on chip.