To investigate the effect of renewable materials on the plastic shrinkage and cracking behavior of mortar, this study selected two renewable materials, glass powder and biochar. Digital image correlation (DIC) technique was employed to quantitatively assess the influence of different dosages (2%, 4%, 6% by cement mass fraction) of glass powder and biochar on the plastic shrinkage and cracking behavior of mortar. The results indicate that the maximum crack width of mortar with glass powder and biochar is smaller than that of the control group without glass powder and biochar. Therefore, adding 2%~6% of glass powder or biochar has a positive effect on the plastic shrinkage and cracking of mortar. Glass powder, due to its smooth surface and hydrophobic nature, enhances the flowability of mortar, but the filling effect and pozzolanic activity of volcanic ash slow down the plastic shrinkage. Biochar, with its porous structure and water absorption capacity, reduces the flowability of mortar, effectively mitigating plastic shrinkage.