Low-temperature iron-capture technology is one of the most promising technologies for recovering platinum group metals from spent automotive catalysts. The iron-capture smelting slag is composed of aluminosilicates and a small amount of toxic heavy metals (Cr, Ba, Ni, Mn). The disposal and resource utilization are difficult. This paper is devoted to the solidification of heavy metals and resource utilization of iron-capture smelting slag. Glass-ceramics were prepared by one-step method, making full use of aluminosilicates as network formers, and heavy metals and CaF2 in pickling sludge as nucleating agents. According to the analysis of differential scanning calorimetry and infrared spectroscopy, the gap between the glass transition temperature and crystallization temperature of the sample decreased from 211 ℃ to 150 ℃ as the amount of pickling sludge increased from 7 wt% to 28 wt%. The devitrification activation energy decreased from 321.8 kJ·mol-1 to 303.5 kJ·mol-1, and the Avrami index increased from 1.7 to 3.7. It shows that the pickling sludge can promote the depolymerization of the glass network structure, stimulate the precipitation of the microcrystalline phase from the glass phase, and shorten the temperature difference between nucleation and crystallization, which is beneficial to the realization of the one-step process. When the addition amount of pickling sludge was 21 wt%, the prepared glass-ceramic had the best properties, namely the density was 3.03 g cm-3, the water absorption was 0.13 wt%, and the Vickers hardness and flexural strength were 707.85 HV and 109.20 MPa. The main crystal phase is diopside phase. The leaching toxicity test showed that heavy metals such as Cr, Ba, and Ni all met the TCLP leaching standard.