This book focuses on the study of heavy quarkonium production at high-energy colliders as a useful tool to explain both the perturbative and non-perturbative aspects of quantum choromodynamics. It provides the first comprehensive comparison between the theory and recent experiments and clarifies some longstanding puzzles in the heavy quarkonium production mechanism. In addition, it describes in detail a new framework for implementing precise computations of the physical observables in quantum field theories based on recently developed techniques. It can be used to simulate the complicated collider environment of the Large Hadron Collider at the Conseil Européen pour la Recherche Nucléaire (CERN). Its accomplishment implies that the Monte Carlo simulations for high-energy physics experiments have reached the limits of precision. It offers readers a wealth of valuable information on the relevant techniques.