Dynamic Binary Instrumentation (DBI) in user space often suffers from low probe insertion success rates and high execution overhead, due to challenges in handling the compact instruction layouts ($\lt $5 bytes) and complex trampoline placement constraints. Existing techniques are either limited in scope, incur high runtime overhead, or rely on heavyweight code relocation. This paper introduces NOProbe, a lightweight, user-space DBI framework that enables safe and efficient probe insertion using two novel strategies. The first strategy locates trampoline sites by leveraging compiler-generated NOP paddings; the second employs pseudo-NOP instructions to support trampoline placement even when instructions overlap. Additionally, we propose a thread-safe patching algorithm,lock-redirect-load-arm, for safe runtime code modification. Experimental results show that NOProbe achieves 97%-99% probe effectiveness, reduces probe insertion latency, and maintains very low per-probe execution overhead, even under high probe density and multithreaded workloads.