This is my master thesis named "High-redshift (z=2~6) Type Ia supernovae on Comological Parameter Estimation and Model Selection". It' about supernova cosmology. The cosmological parameters of LCDM, wCDM models were constrained using Pantheon, Union2.1, mock high-z JWST data trough the maximum likelihood method and the Bayesian method using MCMC algorithm. These models were compared using the reduced chi square, the Bayesian evidence and AIC, BIC.