The observation of ultra-high energy (UHE, E>100 TeV) gamma-ray sources plays a crucial role in identifying Galactic PeV accelerators, also known as PeVatrons. The Large High Altitude Air Shower Observatory (LHAASO) is a large hybrid extensive air shower array, constructed at Haizi Mountain, 4410 m a.s.l., in China. With its wide field of view and high sensitivity, LHAASO is an ideal instrument for the detection and study of PeVatrons within our Galaxy. Since July 2021, the whole LHAASO detector array has been completed and operated in good states. Through an all-sky survey, we have observed ultra-high energy gamma-ray emissions in 43 regions associated with pulsars, supernova remnants (SNR), young star clusters, and other celestial objects. In this proceeding, we will present the results obtained from representative gamma-ray sources and discuss our observations of diffuse gamma-ray emissions along the Galactic plane.