沈光漢,早(zao)年(nian)(nian)曾入粵軍(jun)(jun)第(di)(di)(di)(di)(di)一(yi)(yi)師(shi)(shi)(shi)(shi)軍(jun)(jun)官補習訓(xun)練班受訓(xun)。民國(guo)(guo)十(shi)(shi)四(si)年(nian)(nian)(1925)由(you)蔡(cai)廷(ting)鍇(kai)推薦(jian),任(ren)(ren)(ren)粵軍(jun)(jun)第(di)(di)(di)(di)(di)一(yi)(yi)師(shi)(shi)(shi)(shi)第(di)(di)(di)(di)(di)一(yi)(yi)旅第(di)(di)(di)(di)(di)二(er)團(tuan)(tuan)(tuan)(tuan)(團(tuan)(tuan)(tuan)(tuan)長蔣光鼐)第(di)(di)(di)(di)(di)三(san)營(營長黃質勝(sheng))上(shang)尉營副(fu)。民國(guo)(guo)十(shi)(shi)六(liu)年(nian)(nian)(1927)秋任(ren)(ren)(ren)第(di)(di)(di)(di)(di)十(shi)(shi)師(shi)(shi)(shi)(shi)二(er)十(shi)(shi)八團(tuan)(tuan)(tuan)(tuan)代理團(tuan)(tuan)(tuan)(tuan)長。民國(guo)(guo)十(shi)(shi)八年(nian)(nian)(1929)年(nian)(nian)三(san)月(yue),任(ren)(ren)(ren)廣東編(bian)遣區獨立第(di)(di)(di)(di)(di)二(er)旅(旅長蔡(cai)廷(ting)鍇(kai))上(shang)校副(fu)旅長兼第(di)(di)(di)(di)(di)一(yi)(yi)團(tuan)(tuan)(tuan)(tuan)團(tuan)(tuan)(tuan)(tuan)長(該團(tuan)(tuan)(tuan)(tuan)系(xi)原第(di)(di)(di)(di)(di)十(shi)(shi)師(shi)(shi)(shi)(shi)二(er)十(shi)(shi)八團(tuan)(tuan)(tuan)(tuan)改(gai)編(bian))。是年(nian)(nian)秋,任(ren)(ren)(ren)第(di)(di)(di)(di)(di)六(liu)十(shi)(shi)師(shi)(shi)(shi)(shi)(由(you)獨二(er)旅擴建的)一(yi)(yi)一(yi)(yi)九旅少(shao)將(jiang)旅長。民國(guo)(guo)十(shi)(shi)九年(nian)(nian)(1930)升(sheng)(sheng)十(shi)(shi)九路軍(jun)(jun)六(liu)十(shi)(shi)師(shi)(shi)(shi)(shi)副(fu)師(shi)(shi)(shi)(shi)長(師(shi)(shi)(shi)(shi)長蔡(cai)廷(ting)鍇(kai))。民國(guo)(guo)二(er)十(shi)(shi)年(nian)(nian)(1931)獲四(si)等寶鼎勛(xun)章。是年(nian)(nian)六(liu)月(yue)升(sheng)(sheng)第(di)(di)(di)(di)(di)六(liu)十(shi)(shi)師(shi)(shi)(shi)(shi)中將(jiang)師(shi)(shi)(shi)(shi)長。民國(guo)(guo)二(er)十(shi)(shi)一(yi)(yi)年(nian)(nian)(1932)十(shi)(shi)月(yue),因(yin)“一(yi)(yi)·二(er)八”淞滬(hu)抗日有功,獲青天白日勛(xun)章。民國(guo)(guo)二(er)十(shi)(shi)二(er)年(nian)(nian)(1933)十(shi)(shi)一(yi)(yi)月(yue)“閩(min)變”爆發,任(ren)(ren)(ren)福建人民革命軍(jun)(jun)第(di)(di)(di)(di)(di)一(yi)(yi)方面軍(jun)(jun)第(di)(di)(di)(di)(di)一(yi)(yi)軍(jun)(jun)軍(jun)(jun)長(總司令蔡(cai)廷(ting)鍇(kai))。閩(min)變失敗后(hou)(hou)回住(zhu)香港。民國(guo)(guo)二(er)十(shi)(shi)六(liu)年(nian)(nian)(1937)抗戰軍(jun)(jun)興,出(chu)任(ren)(ren)(ren)軍(jun)(jun)事參議員中將(jiang)參議,很少(shao)在軍(jun)(jun)界(jie)活動。三(san)十(shi)(shi)五(wu)年(nian)(nian)(1946)以后(hou)(hou)被選為第(di)(di)(di)(di)(di)一(yi)(yi)屆國(guo)(guo)民大會(hui)代表,也曾任(ren)(ren)(ren)私立德業小(xiao)學校長。1972年(nian)(nian)11月(yue)29日病(bing)逝于香港,終年(nian)(nian)八十(shi)(shi)五(wu)歲。
1930年(nian),沈(shen)光漢將軍任(ren)十(shi)九(jiu)路軍六十(shi)師(shi)副(fu)師(shi)長(師(shi)長蔡廷(ting)鍇)。
1931年(nian),沈光漢(han)率(lv)所部(bu)第六十師(shi)(shi)駐防蘇州(zhou)、常州(zhou)一(yi)帶。1931年(nian)1月(yue)28日(ri)(ri),日(ri)(ri)軍(jun)進(jin)攻(gong)上海,蔡廷鍇即令沈率(lv)部(bu)開赴上海抗戰。1月(yue)30日(ri)(ri),沈部(bu)到達上海南翔、真茹等地(di)待命。2月(yue)1日(ri)(ri),接替駐在(zai)閘(zha)北、虹口及(ji)八(ba)字橋等處七(qi)十八(ba)師(shi)(shi)的防務(wu)。原七(qi)十八(ba)師(shi)(shi)翁照垣旅劃(hua)歸沈光漢(han)指(zhi)揮,沈師(shi)(shi)遂成為(wei)抗戰主力。七(qi)十八(ba)、六十一(yi)師(shi)(shi)為(wei)總預備隊(dui)。2月(yue)3日(ri)(ri)始,日(ri)(ri)軍(jun)相繼向吳淞、閘(zha)北及(ji)江灣進(jin)犯(fan),沈光漢(han)率(lv)所部(bu)及(ji)配屬部(bu)隊(dui)與之浴血戰斗30多天(tian),雖敵軍(jun)數倍(bei)于己,但沈師(shi)(shi)陣(zhen)地(di)始終屹立不動。尤(you)其(qi)八(ba)字橋陣(zhen)地(di),地(di)處要沖,敵軍(jun)在(zai)飛機、大炮、坦(tan)克的配合下(xia),輪番攻(gong)擊(ji),沈率(lv)部(bu)堅決抵抗,僅2月(yue)7日(ri)(ri)一(yi)天(tian),就殲(jian)日(ri)(ri)軍(jun)千(qian)余(yu)人,擊(ji)燒日(ri)(ri)軍(jun)前(qian)敵指(zhi)揮雨田(tian)大佐。