The secure preservation of germplasm resources serves as a critical foundation for crop breeding, and developing efficient conservation methods for weak-growth accessions is particularly crucial. This study evaluated the growth recovery of 135 accessions of weak sweet potato germplasm. The plants were hydroponically cultured for 21 days and subsequently transplanted into a pot substrates for conservation, with their post-transplant growth performance systematically monitored. The results demonstrated that hydroponic treatment induced robust rooting in weak seedlings, with 71.1% of accessions producing 2–9 roots per plant and 92.6% exhibiting an average root length of 0.4–3.1 cm. Following transplantation, an 82.2% survival rate was recorded at 20 days. By five months, the plants displayed markedly improved growth，with 96% of accessions producing vine lengths exceeding 30 cm, accompanied by a significant increase in branch numbers and 91% attaining stem diameters greater than 3.0 mm. Virus elimination was applied to the hydroponically-rejuvenated accessions, achieving a success rate of 90.1%. The virus elimination significantly restored tuberization capacity of non-tuberizing conventional seedlings. This was marked by 82.4% of accessions with virus-free seedlings achieved a yield exceeding 1000 kg per mu (approximately 6667 kg/ha), whereas only 27.5% of conventional seedlings reached this level. By improving the survival of weak seedlings and securing a critical time window for subsequent virus elimination, this hydroponic rejuvenation technique establishes a reliable and viable method for conservation and rejuvenation of weak seedlings in sweet potato germplasm resources.