Particulate matter in flue gas is one of the major air pollutants during coal combustion. With the development and application of ultra-low emission technologies, filterable particulate matter (FPM) has been effectively controlled. Condensable particulate matter (CPM) passes through dust removal equipment in the gaseous phase and condenses into fine particulate matter after being emitted into the atmosphere. It has become an important source of fine particulate air pollution. Na⁺ is the dominant metal cation in CPM, accounting for 4.23–88.24% of the total metal elements. High-sodium coal is an important fuel for power generation and releases large amounts of gaseous Na during combustion, significantly promoting the formation of fine particles. Previous work has extensively studied the effects and mechanisms of anions such as SO₄^2- and Cl^-, as well as Na, on FPM. However, the sources and formation mechanisms of Na⁺ in CPM have not been reported. In this study, Coals subjected to acid washing, water washing, and sodium salt loading were used to investigate the effect and mechanism of alkali metal Na on CPM formation. The results show that in the CPM generated from high-sodium coal combustion, Na⁺ accounts for more than 60% of the metal cations in the inorganic fraction, and its concentration gradually increases with the Na content in the coal. Water washing effectively removes water-soluble sodium, with removal efficiencies of Na⁺ (80.00%) and Cl^- (51.22%) in CPM superior to those of acid washing. The NaCl content in coal exerts a stagewise effect on ion distribution in CPM. The concentrations of Na⁺ and Cl^- in CPM decreased when the Na content in coal was below 2.02 mg/g, then increased via volatilization and HCl release at 2.02-7.63 mg/g, and decreased through flocculant particle formation at 7.63-16.57 mg/g. Furthermore, different Na species uniformly promotes FPM formation and suppresses CPM generation. Na₂SO₄ decomposition releases substantial sulfur sources, increasing SO₄^2- in CPM by 150.63% and reducing Cl^- by 86.11%. NaCl, Na₂CO₃, and NaAc consume gaseous precursors (SO₂/SO₃ and HCl), thereby inhibiting the formation of SO₄^2- and Cl^- in CPM. These findings reveal the influence mechanisms of Na migration on CPM formation and can provide a theoretical basis for CPM control during the combustion of high-sodium coal.