Magnetic skyrmions, which are topologically non-trivial spin textures that existin symmetry-breaking magnetic materials, are considered to be potential solutions for next-generation magnetic storage and computing technologies. In magnetic multilayer thin films, the repeated ferromagnetic layers and heavy metal layers create interfacial Dzyaloshinskii-Moriya interactions that is favorable to form and stabilize skymrions. Depending on the competing interactions in the system, the spin configuration demonstrates nontrivial dynamical properties under microwave excitations. In this thesis, we study the skyrmion-supporting [Pt/Co/Ru] multilayer thin films in the presence of an out-of-plane magnetic field and an in-plane ac excitation at room temperature. Micromagnetic simulations show two distinct magnetic resonances in the skyrmion phase. One resonance mode is found in the frequency range of 1-5 GHz and another in the range of 7-13 GHz. Skyrmions in resonance gyrate in the clockwise direction in both modes. On the other hand, experimental results show two magnetic resonance peaks in the ferromagnetic resonance and spin-transfer ferromagnetic resonance spectrum. Both resonance modes (acoustic and optic) are identified as uniform dynamical properties with spin configuration precesses in-phase in the acoustic mode and out-of-phase in the optic mode.