DNA-containing block copolymers have utility in a wide range of biomedical applications. However, synthesis of these hybrid materials, especially ones with complex chain structures, remains to be a major challenge. Here, we report the use of a combination of restriction enzyme sites and ligation enzymes to synthesize DNA triblock copolymers. In contrast to triblock structures held together by DNA hybridization, the newly synthesized DNA triblocks have all blocks connected by covalent bonds. The improved stability of the triblocks against environmental factors such as urea denaturing is confirmed. Furthermore, we incorporate a multiple cloning site (MCS) into the DNA block copolymers and show that the restriction sites can be cut by their corresponding restriction enzymes, generating diblocks with different sticky ends. By utilizing these sticky ends of specific sequences, the cut diblocks are further ligated to create a variety of triblock copolymers with different DNA center blocks and synthetic polymer end blocks. This study presents a versatile platform based on MCS for the synthesis and regeneration of a range of DNA-containing block copolymers.