Canada committed to achieve net-zero emissions by 2050, but lacks a sophisticated national-scale energy model to identify optimal transition pathways of the national energy system. To fill this gap, we develop the Canadian Energy Economic and Environmental System Planning Model (Canada-3ESP), a national net-zeroization-oriented energy model designed to facilitate the transition. This model simulates energy flows, greenhouse gas emissions, and economic revenues, refining them with emerging energy technologies across provinces and territories from 2021 to 2050. The model quantitatively characterizes various complexities of the system over both land and marine areas. Through scenario analyses, we assess impacts of different emission-reduction targets on the system, and explore transition strategies such as deployment of renewable energies and carbon-negative technologies (e.g., carbon capture, utilization and storage). Validation against real data from the International Energy Agency strengthens the model's reliability for energy policy formulation. This study finds that, although developing hydropower and phasing out coal-fired generation help meet non-net-zero targets, achieving net-zero emissions requires further decarbonization efforts. Electrification is to be promoted, such as a high electrification rate of 83 % for the transportation sector by 2050, reducing the need for hydrogen and refined petroleum products. To reach net-zero emissions, significant reductions in greenhouse gas emissions are needed, including a 34 % reduction by 2030 and an 81 % reduction by 2050 compared to 2021 levels. The reductions mainly originate from Alberta, Quebec, Ontario, British Columbia, and Saskatchewan. The model aids in crafting a long-term national strategy for sustainable development across all regions. Its insights support informed decision-making, paving the way for sustaining the energy future of Canada.