We propose a novel height measurement method for single nanoparticles illuminated by an evanescent field in the total internal reflection microscopy scheme. The method utilises the scattered light intensity response to incident angle modulation. We introduced a physical model to derive a height measurement formula, and confirmed its validity through numerical simulations based on Maxwell’s equation. We also verified the practical feasibility of the proposed method and confirmed that under an incident angle error of less than 0.1°, height measurement error of less than 10 nm could be achieved.