The Pacific white shrimp (Litopenaeus vannamei ) aquaculture is particularly vulnerable to serious losses associated with the outbreak of white spot and the lack of effective treatment measures for the disease (WSD) caused by the white spot syndrome virus (WSSV). MiRNA, a class of small non-coding RNA, plays a crucial role in RNA interference in response to viral infection. However, the information about shrimp miRNAs regulating viral genes is still limited. As a result, the goal of this work is to find shrimp miRNAs that target WSSV genes and have a therapeutic impact against WSSV infection. First, we investigated miRNA expression data from our in-house RNA sequencing database of unchallenged and 24h-WSSV-challenged shrimp hemocytes and found 1,239 differentially expressed unannotated short RNAs (DEUs). Pva -small RNA-11881 was identified as a potential DEU because it is the most down-regulated DEU and the second biggest node with the most target WSSV gene connections. The sequences of Pva-pre-mir-11881, a possible precursor miRNA of the unannotated Pva -small RNA-11881, were found in the P. vannamei genome, confirming the presence of mature miRNA. As a result, we named it Pva-mir-11881. The potential use of Pva-mir-11881 against WSSV infection in shrimp was investigated. Pva-mir-11818 has shown the ability to knock down WSSV004 , a critical early viral gene, and WSSV419 , a WSSV nucleocapsid protein. Furthermore, injecting shrimp with the recombinant Pva-pre-mir-11881 resulted in a considerable knockdown of WSSV004, WSSV419, and WSSV164 and enhanced anti-melanization activity in hemolymph. Nevertheless, injecting Pva-pre-mir-11881 with WSSV can improve cell homeostasis by modulating program cell death, such as lowering apoptosis and necrosis. When compared to the control group, introducing Pva-pre-mir-11881 can lower the WSSV copy number and increase the survival rate when infected with WSSV. In summary, Pva-mir-11881, a new shrimp miRNA, could play a significant role in WSSV gene regulation, and Pva-pre-mir-11881 might be used as an RNA therapeutic against WSSV infection in shrimp aquaculture.