To address the issues of insufficient mechanical properties and high sensitivity in high-energy gun propellants caused by the addition of large amounts of solid high-energy fillers， by using nitrocellulose as the raw material， isophorone diisocyanate as the coupling agent， and polyethylene glycol as the flexible segment， the ladder-like nitrocellulose （LNC） was prepared via a two-step grafting reaction. LNC was then used as an energetic binder to partially replace nitrocellulose， and a semi-solvent method was adopted to prepare LNC-based double-base gun propellants. LNC formed a double-stranded molecular structure according to the designed reaction pathway. The compatibility， thermal decomposition and sensitivity of LNC-based double-base gun propellants were investigated. Results show that there is good compatibility between LNC and nitrocellulose. The LNC-based double-base gun propellants exhibit enhanced thermal stability with the initial decomposition temperature increased from 190.20 ℃ to 200.89 ℃. The impact sensitivity is reduced with the characteristic drop height value increased from 15.4 cm to 28.2 cm.