[Objective] Liquor wastewater treatment sludge has strong potential as a soil amendment because it is rich innitrogen (N), phosphorus (P), potassium (K) and various trace elements required for plant growth, yet poses minimal heavy-metal risk. Although it shows considerable promise as a soil amendment, its direct application or misuse can harm the environment, soil health and crop performance. This study evaluated whether granulated Liquor sludge could safely and effectively enhance soil physicochemical properties, fertility traits and pepper (Capsicum annuum L.) growth, while mitigating potential soil pollution. [Methods] Pepper plants were cultivated in pots and fertilized with granulated Liquor sludge at rates of 100 ~ 400 kg/667 m2, based on local nutrient requirements calculated from expected yield. A no-sludge control (CK) and a conventional compound chemical fertilizer treatment (F) served as comparisons. [Results] ①The 400 kg/667 m2 sludge treatment (W4) yielded the most pronounced benefits. Compared to CK, soil pH and electrical conductivity (EC) increased by 7.4 % and 59.2 %, respectively; soil organic matter (OM), available phosphorus (AP), available potassium (AK), alkaline nitrogen (AN), ammonium nitrogen (NH??–N) and nitrate nitrogen (NO??–N) contents rose by 72.73 %, 93.28 %, 62.24 %, 24.08 %, 63.40 %, and 14.9 %, respectively. ②The heavy metal content in the soil treated with different methods is far below the standard limit and meets the Class I standard, and the iron (Fe) and aluminum (Al) contents in the treated soil is relatively low, which is not easy to cause soil acidification and compaction; ③Under W4 treatment, pepper plant height and leaf chlorophyll content increased by 68.84 % and 65.48 % versus CK, and fruit yield peaked at 2212 kg/667 m2, significantly surpassing both CK and F. [Conclusion] Granulated Liquor sludge at 400 kg/667 m2 markedly improves soil physicochemical properties and fertility, promotes pepper growth and yield, and maintains heavy metal safety. These results underscore its promise as a sustainable fertilizer and its effectiveness as a soil amendment for boosting pepper productivity and fruit quality.