Heavy-ion collisions (HICs) is a unique experimental tool for investigating the properties of nuclear matter under extreme conditions in the laboratory. At HIRFL-CSR energies, HICs can create nuclear matter with 2–3 times the saturation density ( \(\rho _0\) ). The HIRFL-CSR external-target experiment (CEE) is a large-acceptance spectrometer designed to explore frontier topics in high-energy nuclear physics, such as the QCD phase structure and nuclear matter equation of states. In this letter, we introduce simulation and analysis software for the CEE experiment (CeeROOT). Based on the CEE conceptual design and CeeROOT software, the configurations of its subdetectors were optimized by considering foreseeable physical constraints. The final detector layout of the CEE spectrometer and its acceptances were validated through simulations of U+U collisions at 500 MeV/u and pp collisions at 2.8 GeV, which demonstrated that the CEE experiment will serve as a detector with wide acceptance and multi-particle identification capabilities for studying high-energy nuclear physics topics at HIRFL-CSR energies with pp, pA, and AA collisions.
