Mitochondrial cardiomyopathy (MCM) is a heterogeneous group of disorders characterized by abnormal myocardial structure and/or function caused by defects in genes encoding the oxidative phosphorylation chain. This review systematically summarizes molecular genetic advances regarding nuclear gene mutations associated with pediatric MCM, focusing on mutations affecting pathways including respiratory chain complex subunits and assembly factors, coenzyme Q10 biosynthesis, mitochondrial DNA maintenance and expression, lipid metabolism, iron-sulfur cluster metabolism, apoptosis regulation, and mitochondrial dynamics. These nuclear gene mutations contribute to myocardial pathological changes by disrupting key processes such as mitochondrial energy metabolism, membrane stability, and signal transduction. The review provides a theoretical basis for precise clinical diagnosis and the exploration of potential molecular targets in pediatric MCM. 线粒体心肌病（mitochondrial cardiomyopathy, MCM）是一组由编码氧化磷酸化链的基因缺陷导致心肌结构和/或功能异常的异质性疾病。该文系统综述儿童MCM相关核基因突变的分子遗传学研究进展，重点探讨影响呼吸链复合物亚基及组装因子、辅酶Q10合成、线粒体DNA维持与表达、脂质代谢、铁硫簇代谢、细胞凋亡调控及线粒体动力学等通路的核基因突变。上述核基因突变可通过干扰线粒体能量代谢、膜稳定性及信号传导等关键过程，导致心肌病理改变。该文通过总结核基因突变在儿童MCM发病机制中的作用，为临床精准诊断与潜在分子靶点的研究提供理论依据。.