As sessile organisms, plants rely on cellular homeostasis to cope with various external threats, such as heat, cold, pathogens, and nutrient starvation. Autophagy is one of the cell disposal systems and is crucial for maintaining plant cell homeostasis. Autophagy requires multiple factors, including soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. While the functions of the SNARE proteins in autophagy are well described in yeast and animals, specific roles of SNARE proteins in autophagosome-vacuole fusion are poorly defined in plants. Here, we demonstrate that the vacuolar SNARE SYP22 is essential for autophagosome-vacuole fusion in Arabidopsis. To confirm the general requirement of SNAREs for autophagy, we showed that autophagic flux is diminished by a dominant-negative mutation of the SNARE disassembly factor αSNAP2. Using confocal microscopy and the GFP-ATG8 processing assay, we found that syp22 mutants showed and the accumulation of autophagosomes and reduction in autophagic flux. Furthermore, proteinase K protection assay and transmission electron microscopy (TEM) reveal that syp22 mutant accumulated more closed autophagosomes near the vacuole than wild type. We also detected the interaction of SYP22 with the autophagosomal SNARE VAMP724 on the vacuole-autophagosome contact. In conclusion, our findings demonstrate that SYP22 plays a critical role in mediating autophagosome-vacuole fusion in plants, providing the mechanistic explanation of plant autophagosome turnover.