and rapid prototyping, which has been widely used in myriad of areas, such as lightweight engineering, [4] sensors, [5] the biomedical, [6] flexible electronics [7] and others. [8] Recently, photocuring based 3D printing technologies, which include stereolithography (SLA), [9] digital light processing (DLP), [10] continuous liquid interface production (CLIP), [11] high-area rapid printing (HARP) [12] and two-photon polymerization (TPP), [13] have been drawing great attention in many fields due to their high resolution and printing efficiency properties. [14] Photopolymers, which combine the on-demand, light-triggered fabrication and the robust properties of crosslinked structures, are key materials for 3D printing technologies, especially for photo-curing based 3D printing technology. [15] The demand for 3D printing materials is growing along with the rapidly developing 3D printing industry. [16] However, the chemical cross-linking network makes photopolymers impossible or difficult to reprocess and reuse. [3a,17] Recent advances in the development of covalent adaptable networks (CANs) promote the creating recyclable photopolymers by incorporation of dynamic covalent bonds (DCBs) into structures. [18] Among all the photopolymers, acrylate-based inks or resins exhibit the high-speed of manufacturing and tunable mechanical properties, dominating the photo-resin market of the photocurable 3D printing industry. [19] Thus, the development of acrylate-based CANs photopolymers for 3D printing is of great importance. [20] This approach is exemplified by the work from Zhang and co-workers, [21] who immobilized dynamic hydroxyl-ester bonds into the photopolymers and developed a type of photocurable CANs, which is not only compatible with DLP-based 3D printing, but also reprocessable through bond-exchange reactions. However, the recycling strategy was limited to the traditional hot-pressing approach in this work. To realize the cyclical 3D printing, CANs were crushed and ground into powder or were depolymerized into soluble oligomers assisted with small molecules, and then were formulated with fresh photopolymers for the next round of printing. [22] Notably, in these examples, recovery of photopolymers using CANs generally requires a highly loaded catalyst to activate the dynamic bonds to change the topology, which may be poorly dispersed in the matrix and toxic, leading to poor homogeneity and toxicity of resin materials. [18a,23] Moreover, the recycled materials are usually used as fillers, Photo-curing 3D printing technology has promoted the advanced manufacturing in various fields, but has exacerbated the environmental crisis by the demand for the chemically cross-linked thermosetting photopolymers. Here, the authors report a generic strategy to develop catalyst-free dynamic thermosetting photopolymers, based on photopolymerization and transesterification, that can enable users to realize repeatable 3D printing, providing a practical solution to the environmental challenges. That the β-carbonyl group adjacent t...