In order to realize scalable and integrated quantum photonic networks, various functional devices are highly desired. Strip waveguides with unidirectional transmission function have a wide range of applications in devices such as single-photon diodes, transistors and deterministic quantum gate devices. In this work, the separation of circularly polarized light is achieved by exciting a quantum dot light source in a central region of a waveguide at a low temperature of 4.2 K by using a confocal microscope system. By applying a magnetic field with Faraday configuration (along with the quantum dot growth direction), the spin-momentum locking effect in the waveguide is verified. Both forward shift and reverse shift of different values of output photon energy are demonstrated to show the unidirectional transmission of the waveguide. The chiral transmission of quantum dot with anomalous diamagnetic behavior is achieved in experiment, leading to a wider range of wavelength tuning for chrial transmission in a single waveguide. This paper provides a basis for investigating the chiral quantum devices in a wide wavelength range and expands the applications of waveguides in the field of optical quantum information.