Abstract : In this paper, strongly cotorsion (torsion-free) modules are studied and strongly cotorsion (torsion-free) dimension is introduced. It is shown that every module has a special $\mathcal{S}\mathcal{C}_n$-preenvelope and an $\mathcal{S}\mathcal{T}\mathcal{F}_n$-cover for any $n\in\mathbb{N}$ based on some results of cotorsion pairs from [9]. Some characterizations of strongly cotorsion (torsion-free) dimension of a module are given.