Abstract How to increase the stereocomplex crystal (SCs) content of polylactic acid attracts a lot of attention from scientists. In the current work, Monte Carlo simulations are used to construct grafted diblock copolymer systems with different grafting modes and the stereocomplex crystallization of these systems is studied. The results show that the SC contents are highest in the random‐grafted, the row‐staggered‐grafted and the point‐staggered‐grafted copolymer systems, while the SC content is lowest in the uniform‐grafted copolymer systems. This can be attributed to that the random‐grafted, the row‐staggered‐grafted and the point‐staggered‐grafted copolymer systems have the highest local segment miscibility, while the uniform‐grafted copolymer system has the lowest local segment miscibility. In addition, it is also found that the point‐staggered‐grafted copolymer systems with lower chain lengths exhibit higher SC contents due to the stronger segment mobility.